Decline In Enzyme Activity Research Articles

Immobilization of the β-galactosidase enzyme by encapsulation in polymeric matrices for application in the dairy industry

Lactose intolerance affects approximately 65% of the global adult population, leading to the demand for lactose-free products. The enzyme β-galactosidase (βG) is commonly used in the industry to produce such products, but its recovery after lactose hydrolysis is challenging. In this scenario, the study aims to encapsulate βG within capsules, varying in dimensions and wall materials, to ensure their suitability for efficient industrial recovery. The enzyme βG was encapsulated through ionic gelation using alginate and its blends with pectin, maltodextrin, starch, or whey protein as wall materials. The capsules produced underwent evaluation for encapsulation efficiency, release profiles, activity of the βG enzyme, and the decline in enzyme activity when reused over multiple cycles. Alginate at 5% wt/vol concentrations, alone or combined with polymers such as maltodextrin, starch, or whey protein, achieved encapsulation efficiencies of approximately 98%, 98%, 80%, and 88%, respectively. The corresponding enzyme recovery rates were 34%, 19%, 31%, and 48%. Capsules made with an alginate-pectin blend exhibited no significant hydrolysis and maintained an encapsulation efficiency of 79%. Encapsulation with alginate alone demonstrated on poor retention of enzyme activity, showing a loss of 74% after just 4 cycles of reuse. Conversely, when alginate was mixed with starch or whey protein concentrate, the loss of enzyme activity was less than 40% after 4 reuses. These results highlight the benefits of combining encapsulation materials to improve enzyme recovery and reuse, offering potential economic advantages for the dairy industry.

Dynamic Changes of Phenolic Composition, Antioxidant Capacity, and Gene Expression in 'Snow White' Loquat (Eriobotrya japonica Lindl.) Fruit throughout Development and Ripening.

The newly released 'Snow White' (SW), a white-fleshed loquat (Eriobotrya japonica Lindl.) cultivar, holds promise for commercial production. However, the specifics of the phenolic composition in white-fleshed loquats, along with the antioxidant substances and their regulatory mechanisms, are not yet fully understood. In this study, we examined the dynamic changes in the phenolic compounds, enzyme activities, antioxidant capacity, and gene expression patterns of SW during the key stages of fruit development and ripening. A total of 18 phenolic compounds were identified in SW, with chlorogenic acid, neochlorogenic acid, and coniferyl alcohol being the most predominant. SW demonstrated a stronger antioxidant capacity in the early stages of development, largely due to total phenolics and flavonoids. Neochlorogenic acid may be the most significant antioxidant contributor in loquat. A decline in enzyme activities corresponded with fruit softening. Different genes within a multigene family played distinct roles in the synthesis of phenolics. C4H1, 4CL2, 4CL9, HCT, CCoAOMT5, F5H, COMT1, CAD6, and POD42 were implicated in the regulation of neochlorogenic acid synthesis and accumulation. Consequently, these findings enhance our understanding of phenolic metabolism and offer fresh perspectives on the development of germplasm resources for white-fleshed loquats.

Comprehensive analysis reveals the differentiated influential mechanism of degradable poly (ε-caprolactone) and polybutylene succinate microplastics on nitrogen transformation in aerobic granular sludge systems

The escalating releasing of degradable microplastics (DMPs) into wastewater may pose a potential threat to biological nitrogen removal. However, whether and how different DMPs affect nitrogen transformations in aerobic granular sludge (AGS) systems remains unclear. This work therefore aimed to fill such knowledge gaps by employing poly (ε-caprolactone) (PCL) and polybutylene succinate (PBS) as the model microplastics. Results revealed that exposure to 0.5 and 5 mg/L DMPs did not remarkably affect the nitrogen removal. However, increasing DMPs concentration to 50 mg/L suppressed the nitrogen transformation, causing a significant degree of inhibition in total nitrogen removal efficiency, particularly in the PCL-exposure group (decreased by 2.0%–25.7%). The pronounced inhibitory effects were attributed to the more readily biodegradability of PCL compared to PBS, resulting in an enhanced release of microplastics that induced excessive production of reactive oxygen species and destruction of cytomembrane integrity. Consequently, the relative abundance of denitrifiers was decreased, leading to suppressed expression of the genes (e.g. narG) involved in nitrogen transformation. This was accompanied by a decline in enzyme activity (e.g. nitrate reductase) and electron transport system activity. The correlations among genes, microbes and environmental factors were reshaped by different DMPs, underlying the intrinsic mechanism for the deteriorated nitrogen removal. Overall, this study implies that compared to PBS microplastics, the accumulation of PCL microplastics in aquatic environments poses a more significant threat to biological treatment efficacy and global nitrogen cycling, thereby warranting increased attention.

Process intensification of lipase catalyzed isopropyl ester synthesis by integration with hydrophilic pervaporation: Experimental results, engineering aspects and techno-economic analysis

This work reports an integrated reaction and separation process for the enzymatic synthesis of isopropyl palmitate (IPP) and isopropyl laurate (IPL). Experimental tests for IPP synthesis integrated with hydrophilic pervaporation mode demonstrated the potential of the technology with a stable performance (∼99% fatty acid conversion) without decline in enzyme activity and membrane performance over 5 consecutive tests. A techno-economic analysis was made for a facility producing 2000 metric tons of IPL per annum using the experimental results. Furthermore, a hybrid mathematical model was developed incorporating both mechanistic and empirical features. Comparison of model results with the experimental data led to the identification of areas which need further improvement. Pervaporation integrated with lipase catalyzed solvent free synthesis of IPP and IPL has not been reported so far. Hence, the findings presented in this study provide a valuable insight into these technologies. More importantly, the developed systematics can be extended to the solventless production of other important esters.

Unravelling inclusion body myositis using a patient-derived fibroblast model.

Inclusion body myositis (IBM) is an inflammatory myopathy clinically characterized by proximal and distal muscle weakness, with inflammatory infiltrates, rimmed vacuoles and mitochondrial changes in muscle histopathology. There is scarce knowledge on IBM aetiology, and non-established biomarkers or effective treatments are available, partly due to the lack of validated disease models. We have performed transcriptomics and functional validation of IBM muscle pathological hallmarks in fibroblasts from IBM patients (n=14) and healthy controls (n=12), paired by age and sex. The results comprise an mRNA-seq, together with functional inflammatory, autophagy, mitochondrial and metabolic changes between patients and controls. Gene expression profile of IBM vs control fibroblasts revealed 778 differentially expressed genes (P-value adj<0.05) related to inflammation, mitochondria, cell cycle regulation and metabolism. Functionally, an increased inflammatory profile was observed in IBM fibroblasts with higher supernatant cytokine secretion (three-fold increase). Autophagy was reduced considering basal protein mediators (18.4% reduced), time-course autophagosome formation (LC3BII 39% reduced, P-value<0.05), and autophagosome microscopic evaluation. Mitochondria displayed reduced genetic content (by 33.9%, P-value<0.05) and function (30.2%-decrease in respiration, 45.6%-decline in enzymatic activity (P-value<0.001), 14.3%-higher oxidative stress, 135.2%-increased antioxidant defence (P-value<0.05), 11.6%-reduced mitochondrial membrane potential (P-value<0.05) and 42.8%-reduced mitochondrial elongation (P-value<0.05)). In accordance, at the metabolite level, organic acid showed a 1.8-fold change increase, with conserved amino acid profile. Correlating to disease evolution, oxidative stress and inflammation emerge as potential markers of prognosis. These findings confirm the presence of molecular disturbances in peripheral tissues from IBM patients and prompt patients' derived fibroblasts as a promising disease model, which may eventually be exported to other neuromuscular disorders. We additionally identify new molecular players in IBM associated with disease progression, setting the path to deepen in disease aetiology, in the identification of novel biomarkers or in the standardization of biomimetic platforms to assay new therapeutic strategies for preclinical studies.

Physiological and molecular responses to hypoxia stress in Manila clam Ruditapes philippinarum

Hypoxia has become one of the major environmental problems in the aquaculture industry. As one of the most commercially important bivalves, Manila clam Ruditapes philippinarum may be suffering substantial mortality attributable to hypoxia. The physiological and molecular responses to hypoxia stress in Manila clam were evaluated at two levels of low dissolved oxygen: 0.5 mg/L (DO 0.5 mg/L) and 2.0 mg/L (DO 2.0 mg/L). With the prolongation of hypoxia stress, the mortality rate was 100% at 156 h under DO 0.5 mg/L. In contrast, 50% of clams survived after 240 h of stress at DO 2.0 mg/L. After the hypoxia stress, some severe structural damages were observed in gill, axe foot, hepatopancreas tissues, such as cell rupture and mitochondrial vacuolization. For the hypoxia-stressed clams, the significant rise and decline of enzyme activity (LDH and T-AOC) was observed in gills, in contrast to the reduction of glycogen content. Furthermore, the expression levels of genes related to energy metabolism (SDH, PK, Na+/K+-ATPase, NF-κB and HIF-1α) was significantly affected by the hypoxia stress. It is therefore suggested that the short-term survival of clams under hypoxia may be dependent on stress protection by antioxidants, energy allocation, and tissue energy reserves (such as glycogen stores). Despite this, the prolongation of hypoxia stress at DO 2.0 mg/L may cause the irreversible damages of cellular structures in clam tissues, eventually leading to the death of clams. We therefore support the hypothesis that the extent of hypoxia impacts on marine bivalves may be underestimated in the coastal areas.

Alleviating effect of mulberry leaf 1-deoxynojirimycin on resistin-induced hepatic steatosis and insulin resistance in mice.

Resistin is upregulated in obese humans and mice, and elevated serum resistin induces insulin resistance and hepatic steatosis. Previous studies have revealed that mulberry 1-deoxynojirimycin (DNJ) is important for a variety of physiological processes, especially carbohydrate and lipid metabolism. However, it remains unclear whether DNJ has a positive effect on insulin resistance and hepatic steatosis, and what the exact mechanism is. Male C57BL/6J mice were treated with resistin with or without DNJ. DNJ reversed the homeostasis model assessment of insulin resistance (HOMA-IR)-induced by resistin and significantly decreased triglyceride levels both in the serum and liver. A histological analysis demonstrated that lipid accumulation significantly decreased in the DNJ group compared to the resistin group. A mechanistic analysis showed that DNJ significantly inhibited the resistin-induced decline in enzyme activities of hormone-sensitive lipase (HSL) and hepatic lipase (HL) in serum and lipoprotein lipase (LPL) in liver. FAS and Acox13α were significantly altered by resistin but restored by DNJ. Furthermore, DNJ partially but significantly restored insulin-stimulated glucose uptake compared with the resistin group, suggesting that DNJ reversed the insulin sensitivity impaired by hyperresistinemia. Treatment of AML12 cells with DNJ significantly restored the expression level and phosphorylation of Akt. The transcriptional levels of InsR and IRS1, as well as the protein levels of InsR and Glut4 and phosphorylation of PI3K and GSK3β, were also normalized in the DNJ-treated group. In conclusion: mulberry DNJ significantly alleviated liver steatosis and insulin resistance in hyperresistinemia.

Effects of betaine on growth performance, intestinal health, and immune response of goslings challenged with lipopolysaccharide

The objective of this experiment was to investigate the effects of betaine on growth performance, serum parameters, intestinal health, and immune performance of goslings in response to lipopolysaccharide (LPS) challenge. A total of 168 healthy male 15-day-old Jiangnan White Goslings were randomly divided into 4 groups, with 6 replicates per treatment and seven goslings per replicate. A 2 × 2 factorial arrangement included 2 factors, that is, LPS challenge (injection of LPS or physiological saline) and betaine (added 0 or 0.06% betaine in diet). The results indicated that LPS challenge significantly reduced the average daily feed intake (ADFI), average daily gain (ADG), and body weight (BW) at 21 D of the goslings, while dietary betaine supplementation tended to increase the ADFI during the LPS stress period (P = 0.08) and BW at 21 D of the goslings (P = 0.09). The LPS-challenged goslings showed higher pro-inflammatory cytokines (interleukin-1 [IL-1β], interleukin-6 [IL-6], tumor necrosis factor-α (TNF-α), and Interferon-gamma [IFN-γ]) and lower anti-inflammatory cytokine (Interleukin-10 [IL-10]) (P < 0.05) at 21 D of age. Dietary betaine supplementation alleviated LPS-induced increase in pro-inflammatory cytokines. The LPS challenge significantly decreased duodenal and jejunal villus height (VH) and villus height and crypt depth ratio (VCR), while the addition of betaine significantly increased duodenal VH and VCR (P < 0.05). On the other hand, addition of betaine significantly alleviated decline of enzyme activity on lipase, amylase, trypsin, and chymotrypsin in the intestinal of goslings. The LPS challenge significantly increased the content of serum D-lactic acid (D-LA) and the activity of diamine oxidase (DAO) at 21 D of the goslings. The LPS challenge and betaine addition significantly increased the mRNA expression of Occcludin (OCLN) in jejunal mucosa at 28 D of the goslings (P < 0.05). In conclusion, our research demonstrated that betaine can alleviate the decline of growth performance and immune performance in goslings caused by LPS. The results also indicate betaine possesses anti-inflammation properties and improves intestinal barrier functions. We recommend that 0.06% betaine be added into the diet to improve the intestinal health and immune performance of goslings.

Soil enzyme activities after application of fungicide Quadris&lt;sup&gt;R&lt;/sup&gt; at increasing concentration rates

The study aimed to assess the effects of fungicide QuadrisR on activities of soil enzymes contributed to soil nutrient turnover. A batch laboratory experiment with QuadrisR-amended (0 mg/kg ds (dry soil) – 35.00 mg/kg ds) loamy sand soil was conducted, and shifts in soil physical environments and enzyme activities (beta-glucosidase, urease, acid and alkaline phosphatases, arylsulfatase and dehydrogenase) were evaluated on experimental days 1, 30, 60, 90 and 120. The results indicated that QuadrisR changed both soil properties and enzyme activities. The most sensitive environmental parameter to fungicide input was soil pH. The most suscaptable to QuadrisR enzymes were dehydrogenase and arylsulfatase, and the most resistant – urease. The mean overall dehydrogenase activity decreased by 33%, whereas the profile of arylsulfatase activity tended to permanent decrease over time. The general pattern of enzyme responses to QuadrisR was an immediate-early (days 1 – 30) decline of enzyme activities after fungicide application, except that of arylsulfatase. Beta-glucosidase manifested a temporal profile of steady-state stimulation under the lowest (2.90 mg/kg ds) and low sensitivity to the higher (14.65 mg/kg ds and 35.00 mg/kg ds) fungicide concentrations.

Effects of decomposition on the recoverability of biological fluid evidence.

The present research assessed how the physical and chemical changes associated with decomposition affect the detection and identification of blood and semen evidence, as well as subsequent DNA analysis. A feeder pig (postmortem interval (PMI) < 3h) was placed within the Boston University Outdoor Research Facility for a period of 22days. Human blood and semen were individually dispensed onto multiple areas of two cotton t-shirts; one layer of fabric was placed above and below the pig and a control. One of each sample type was collected per day for a period of 22days from each location. It was observed that both sample types when collected from beneath the pig exhibited the greatest decline in enzymatic activity over the course of testing, followed by samples from beneath the control, which can be inferred from the increase in negative screening results compared to the other samples. Spermatozoa were observed in nearly all semen samples, even when all screening results were negative, which lead to the generation of comparable DNA profiles for nearly all semen samples typed. Genetic typing of the blood samples beneath the pig and control rarely yielded comparable data while the samples from above yielded full profiles for all but a few samples tested.

Physico-chemical and Enzymatic Changes in Cold Stored ‘Dusehri’ Mango Fruits in Response to Beeswax and &lt;i&gt;Aloe Vera &lt;/i&gt;Gel Coatings

Mango is harvested in summer months and exhibits short postharvest life due to rapid biochemical changes. These ripening changes occur even at low temperature storage, though at slower rates. Hence, the effect of Aloe vera gel (AVG) and beeswax coatings on physico-chemical parameters and enzymatic activities in mango cv. Dusehri were evaluated for 28 days under low temperature (9-11 °C, 90-95 % RH). Fruits were coated with AVG (50 and 100 %) and beeswax (1.5 and 3.0 %) while control fruits were left uncoated. As compared to control, both AVG and beeswax coatings significantly delayed the pulp colour development in fruits throughout the storage. These coatings also reduced weight loss and maintained titratable acidity in mango fruits. At 21st day of storage, beeswax 3.0 % coated fruits retained 54.06 % higher fruit firmness and 43.18 % lower weight loss than the untreated fruits. Both edible coatings efficiently retarded the polygalacturonase (PG) and cellulase activities as compared to control fruits. In coated fruits, the enzymatic activities increased up to 21 days of storage, while the control fruits exhibited a decline in enzymatic activities after 14 days. The beeswax coatings were more effective in increasing the storage life of mango fruits under low temperature conditions.

Technological characterisation of potential malolactic starters from Rioja Alavesa winemaking region

Technological characterisation of 22 strains of lactic acid bacteria belonging to Oenococcus oeni, Lactobacillus mali and Lactobacillus plantarum species has been carried out in order to elucidate their oenological potential as malolactic starters. After analysing their behaviour against typical harsh conditions found in wine as well as their malolactic fermentation vigour, the better suitability of O. oeni strains was confirmed. These O. oeni strains were further characterised for multiple enzyme activities. Both molecular and phenotypical methods confirmed citrate catabolising ability of all strains. Glycosidase (α-glucosidase, β-glucosidase, β-xylosidase and α-arabinosidase) and esterase activities under different pH and ethanol concentration combinations were also quantified. All strains exhibited α-glucosidase, β-glucosidase and esterase activity. Conversely, only few strains showed β-xylosidase and α-arabinosidase activity. A synergistic negative effect of pH and ethanol on enzyme activity was observed under the most extreme conditions, in that way, when ethanol concentration was more aggressive, a sift to lower pH was traduced on significant enzyme activity decline. However, many strains still retained detectable activities. These results encourage the potential use of many of the characterised autochthonous O. oeni strains as an effective strategy to perform a reliable MLF and to enhance wine aroma complexity in Rioja Alavesa region.

Accelerated microbial activity, turnover and efficiency in the drilosphere is depth dependent

Anecic earthworms such as Lumbricus terrestris create effective channels for the translocation of organic substances, nutrients (N, P) and water between top- and subsoil. However, studies on localized and linked microbial activities with the biochemical mechanisms within drilosphere are missing. To clarify the enzymatic mechanisms, zymography was combined with 14C imaging by placing 14C-labeled wheat litter on the surface of mesocosms with top- and subsoil to feed earthworms. Cellobiohydrolase and acid phosphatase activities were compared in drilosphere and bulk soil to test two hypotheses: i) a positive spatial correlation between 14C images and enzyme activities at burrow edges reflects the interactions between substrate distribution and microbial activities; ii) the drilosphere has higher enzyme activities and faster substrate turnover compared to bulk soil independent on depth. In line with the first hypotheses, the localization of substrates (14C) overlapped with enzyme activities for 68%. Spatial distribution of enzyme activities had stronger gradients within 2 mm of burrow edges in topsoil and 4 mm in subsoil. The mineralization of the wheat litter was faster in drilosphere than in the bulk soil. In contrast to our second hypothesis, the substrate turnover was depth dependent: 14CO2 efflux was fourfold faster in topsoil than subsoil drilosphere. The decline of enzyme activities with depth, accompanied by decreasing catalytic efficiency, implies microbial production of more efficient enzymes in top-than in the subsoil.We conclude that interactions between enzymes and substrates are more tight in the drilosphere, making it microbial hotspots. Thus, earthworm activities lead to microbial localization and acceleration of litter decomposition and C turnover in drilosphere. Therefore, both direct hotspot and indirect (soil heterogeneous content) effects need to be explicitly considered when attempting to model and predict how bioturbation evens will alter ecosystem dynamics and ecological development of (micro)habitats.

Evaluation rachis browning phenomena of ‘Superior Seedless’ vines grafted on different rootstocks during shelf life

Rachis browning phenomena during shelf life is an important issue faced by grapes trading. The experiment was carried out during two growth seasons (2017–2018) to evaluate the effect of 'Superior Seedless' rootstocks such as ‘Freedom’, ‘SO4’, ‘1103 Paulsen’, and ‘own-roots on rachis fruit clusters browning phenomena were tested during shelf life. Fruit cluster samples were harvested from commercial vineyard when total soluble solids reached 16° Brix. Thereafter, bunches were stored at ambient temperature (26 ± 1 °C and 45 ± 1 RH% air relative humidity) for four days as a shelf life experiment. Samples selected everyday interval as for physical properties and chemical determinations. The results pointed out that the '1103 Paulsen' rootstock decreased the water loss percentage, rachis browning symptoms, and improved berries color hue angle. Moreover, a significant decline in enzyme activities of cellular walls such as polygalacturonase (PG; EC:3.2.1.15), and lipoxygenase (LOX; EC:1.13.11) monitored. Consequently, ‘1103 Paulsen’ minimized the malondialdehyde (AMD) accumulation and cell membrane cellular ionic permeability during four days of shelf life. Lately, both browning enzymes PPO and PAL diminished. Thus, preserving the phenolic compounds accompanied by less browning incidence on fruit rachis during the shelf-life period. Overall, ‘1103 Paulsen’ minimize the browning symptoms of ‘Superior seedless’ grapes were grafted on four rootstocks during shelf life stress/marketing.

Novel mRNA-Based Therapy Reduces Toxic Galactose Metabolites and Overcomes Galactose Sensitivity in a Mouse Model of Classic Galactosemia.

Classic galactosemia (CG) is a potentially lethal inborn error of galactose metabolism that results from deleterious mutations in the human galactose-1 phosphate uridylyltransferase (GALT) gene. Previously, we constructed a GalT-/- (GalT-deficient) mouse model that exhibits galactose sensitivity in the newborn mutant pups, reduced fertility in adult females, impaired motor functions, and growth restriction in both sexes. In this study, we tested whether restoration of hepatic GALT activity alone could decrease galactose-1 phosphate (gal-1P) and plasma galactose in the mouse model. The administration of different doses of mouse GalT (mGalT) mRNA resulted in a dose-dependent increase in mGalT protein expression and enzyme activity in the liver of GalT-deficient mice. Single intravenous (i.v.) dose of human GALT (hGALT) mRNA decreased gal-1P in mutant mouse liver and red blood cells (RBCs) within 24h with low levels maintained for over a week. Repeated i.v. injections increased hepatic GalT expression, nearly normalized gal-1P levels in liver, and decreased gal-1P levels in RBCs and peripheral tissues throughout all doses. Moreover, repeated dosing reduced plasma galactose by 60% or more throughout all four doses. Additionally, a single intraperitoneal dose of hGALT mRNA overcame the galactose sensitivity and promoted the growth in a GalT-/- newborn pup.

Inhibitory mechanism of epicatechin gallate on α-amylase and α-glucosidase and its combinational effect with acarbose or epigallocatechin gallate

Suppression of α-amylase and α-glucosidase is favorable for improvement of postprandial hyperglycemia. Here, the inhibitory mechanisms of epicatechin gallate (ECG) on α-amylase and α-glucosidase are explored by enzyme kinetics, spectroscopy and molecular modeling approaches. ECG was found to have strong inhibitory efficiency against α-amylase and α-glucosidase in mixed−type manners with IC50 values of 45.30 ± 0.22 and 4.03 ± 0.01 μg/mL, respectively. ECG bound to α-amylase and α-glucosidase forming ECG–α-amylase and ECG–α-glucosidase complexes, causing the conformational changes of the enzymes. Molecular simulation exhibited that ECG located into the active pocket of the enzymes likely contributed by some major amino acid residues Gln63 and Asp197 of α-amylase, and Lys156, Ser157, Arg315 and Asp352 of α-glucosidase, which may prevent the entrance of substrate leading to a decline in enzyme activity. Meanwhile, at the constant IC50 ratios of ECG to acarbose or epigallocatechin gallate, an obvious antagonism was observed in α-amylase inhibition, while additive and synergistic effects for α-glucosidase. These findings suggest that ECG may be a potential inhibitor of α-amylase and α-glucosidase, which could be used as a nutrient supplement for the prevention of diabetes mellitus.

Effects of High and Low Glycemic Load of Different Nigerian Food Forms on Rats Brain and Heart Mitochondrial Integrity

The present study was designed to investigate the effect of glycemic load (GL) on brain and cardiac mitochondrial integrity. The effect of high glycemic load (HGL) and low glycemic load (LGL) diets on the generation of free radicals and its consequent effect on brain and cardiac mitochondrial were assessed. The effect of the reactive oxygen species (ROS) on the activities of electron transport chain (ETC) was examined. A significant decline in enzyme activities of complex I, III and IV were observed, for both brain and cardiac mitochondria ETC. Brain rotenone-sensitive complex I activities decreased by 49.20% (p>0.05) in HGL-fed rats, while antimycin-a sensitive complex III decreased by 19.80% (p>0.05). Same phenomenon was observed in potassium cyanide (KCN)-sensitive complex IV (cytochrome c oxidase), which decreased by 30.17% (p>0.05). For cardiac mitochondrial complexes, Rotenone-sensitive complex I decreased by 25.45% (p>0.05) in HGL fed group, while antimycin-a sensitive complex III activity decreased by 24.78% (p>0.05). Glycemic related changes were also observed in KCN-sensitive complex IV with a decrease of 21.18% (p>0.05). Enzyme activities in both brain and cardiac mitochondrial homogenates decrease minimally in LGL fed rats, compared with the control. Thiol group content, total protein and malondialdehyde (MDA) were found to be significantly elevated in rats fed with HGL diet. Superoxide dismutase (SOD) and catalase (CAT) enzymes activities decreased in both brain and cardiac mitochondria of rats fed with HGL diets. It can be concluded that low glycemic load diet sustains the mitochondrial integrity. Whereas, HGL diets induced oxidative stress and degenerates antioxidant enzymes activities in brain and heart mitochondria; thereby inducing loss of mitochondrial integrity.

Evaluation of enzyme activity and rate of tooth movement in corticotomy-accelerated tooth movement - A randomized clinical trial.

BACKGROUND:This study was undertaken to evaluate the enzyme activity profiles in human saliva and gingival crevicular fluid (GCF) in accelerated tooth movement when compared with normal orthodontic tooth movement (OTM) in extraction cases.MATERIALS AND METHODS:Twenty patients who required premolar extractions were treated with MBT mechanotherapy. They were divided into two equal groups: conventional (Group I) and corticotomy (Group II) which was performed on both the jaw sides before initiating retraction. GCF was collected from mesial and distal aspects of canine before initiation of retraction and at 7th, 14th, 21st, and 28th days, and then at fifth and sixth weeks and third and sixth months after retraction. A total of 5 mL of unstimulated saliva was collected from the subjects after 90 min of nonoral activity (subjects were refrained from eating and drinking).RESULTS:The results showed that in Group I, the peak of aspartate aminotransferase (AST) and alkaline phosphatase (ALP) enzyme activity occurred on the 14th day of force application. In Group II, the enzyme activity progressively increased from day 0 to 6 weeks, peaking at the sixth week, and then a decline in enzyme activity was observed on third and sixth months. When ALP and AST activities in GCF and saliva were compared between Groups I and II, no statistically significant difference was observed on days 0, 7, and 14.CONCLUSION:Corticotomy-accelerated tooth movement is a promising technique that has many applications in orthodontic treatment of adults as it helps overcome many of the current limitations of this treatment. The enzymatic activity signifies osteoclastic and osteoblastic activities, so ALP and AST from the saliva and GCF may potentially be used as biomarkers for monitoring corticotomy-assisted OTM.

ENZYME ACTIVITY IN RELATION TO TOTAL K, Ca, Mg, Fe, Cu AND Zn IN THE OIL PALM RHIZOSPHERE OF RIAU’S PEATLANDS, INDONESIA

Enzyme activity can be used as a peat decomposition indicator in the oil palm rhizosphere of peatlands. Oil palm plantation management requires fertilization in the rhizosphere to provide nutrients for oil palm growth. The state of total nutrient in the rhizosphere can influence enzyme activity. This research aimed to study enzyme activity in relationship to nutrients in the oil palm rhizosphere of peatlands. Using the explorative method in Riau’s tropical peatlands, an oil palm plantation was chosen as a location for the main sites, and a degraded forest as well as a shrubland were chosen as comparison sites. In the oil palm plantation, peat samples were taken from peats adhering to oil palm roots at the peat depths of 0‒25 and 25‒50 cm and at distances of 0‒1, 1‒2, 2‒3, and 3‒4 m from the trees. In the degraded forest and shrub, t samples were taken from selected plant roots at the depths of 0-25 and 25-50 cm. The triplicate peat samples were then composited for an analysis of enzyme activity and total nutrient content. Results showed that enzyme (urease, phosphatase, β-glucosidase, and laccase) activity in the oil palm rhizosphere decreased as the distance from trees and the depth of rhizosphere increased. The decline in enzyme activity was caused by a low peat pH and an increased water content as well as organic carbon content. Enzyme activity increased with increasing oil palm age and ash content. Total K and Zn contents showed no correlation with enzyme activities. However, total Ca and Mg contents showed positive correlation only with β-glucosidase activity. Total Fe and Cu contents showed significantly negative correlation with enzyme activities (urease, phosphatase, β-glucosidase, and laccase). Enzyme activity in the rhizosphere of the degraded forest and shrubs were mostly lower than in the oil palm rhizosphere.

Biophysical characterization of a recombinant lipase KV1 from Acinetobacter haemolyticus in relation to pH and temperature

Spectroscopic and calorimetric methods were employed to assess the stability and the folding aspect of a novel recombinant alkaline-stable lipase KV1 from Acinetobacter haemolyticus under varying pH and temperature. Data on far ultraviolet-circular dichroism of recombinant lipase KV1 under two alkaline conditions (pH 8.0 and 12.0) at 40 °C reveal strong negative ellipticities at 208, 217, 222 nm, implying its secondary structure belonging to a α + β class with 47.3 and 39.0% ellipticity, respectively. Results demonstrate that lipase KV1 adopts its most stable conformation at pH 8.0 and 40 °C. Conversely, the protein assumes a random coil structure at pH 4.0 and 80 °C, evident from a strong negative peak at ∼ 200 nm. This blue shift suggests a general decline in enzyme activity in conjunction with the partially or fully unfolded state that invariably exposed more hydrophobic surfaces of the lipase protein. The maximum emission at ∼335 nm for pH 8.0 and 40 °C indicates the adoption of a favorable protein conformation with a high number of buried tryptophan residues, reducing solvent exposure. Appearance of an intense Amide I absorption band at pH 8.0 corroborates an intact secondary structure. A lower enthalpy value for pH 4.0 over pH 8.0 and 12.0 in the differential scanning calorimetric data corroborates the stability of the lipase at alkaline conditions, while a low Km (0.68 ± 0.03 mM) for tributyrin verifies the high affinity of lipase KV1 for the substrate. The data, herein offer useful insights into future structure-based tunable catalytic activity of lipase KV1.