Kinds Of Enzymes Research Articles

Trichoderma reesei Cellulase Complex in Hydrolysis of Agricultural Waste of Grapefruit Peel and Orange Peel

Previous attempts have already been performed for the production of sugars and, later, bioproducts from orange peel using different Trichoderma reesei commercial cocktails in combination with other kinds of enzymes. In this study, the feasibility of simple pretreatments combined with enzymatic treatments was compared between grapefruit inner peel (GFIP), orange inner peel (OIP), grapefruit whole peel (GFWP), and orange whole peel (OWP). The four biomaterials were characterized with respect to the contents of cellulose and hemi-cellulose, elemental analysis, and Fourier transform infrared (FTIR) spectrometry. The 3,5-dinitrosalicylic acid assay demonstrated that GFIP and OIP produced 31.7% and 34.9% more reducing sugar than GFWP and OWP, respectively. Further investigation of the bioprocess showed the optimal conditions include the following: (i) a solid to liquid ratio of 4%, (ii) enzymatic activity of 0.075 U/mL, and (iii) reaction at 55 °C and a pH of 5.0. Moreover, the major products after cellulolytic hydrolysis were fructose, glucose, and cellobiose. This study provides an alternative and effective approach to extend the utilization of agricultural waste in the fields of food and energy.

참외 저급과 주스의 청징화를 위한 효소처리 조건

In Gyeongsangbuk-do seongju area, hundreds of tons of spoiled oriental melon are harvested annually. Therefore, ways to prevent such spoilage are needed. This study was conducted to investigate the quality characteristics of spoiled oriental melon juice after enzyme treatment for the production of oriental melon concentrate. The treatment of the oriental melon juice with three kinds of enzymes with variable concentrations showed the following results. PECE(1), which was compounded pectinase and cellulase at 0.01% (v/v), gave the melon a 0.16 brown color and 0.01 turbidity, and the highest L value of 97.00. The detected free sugar contents were fructose, glucose and sucrose, with the amount of sucrose the highest at roughly 4,000 mg%. The mixture of different enzyme treatments resulted in a 0.15 brown color and 0.01 turbidity at 60 minutes, and the L value was high at 97.25. The enzyme treatment temperatures of 50℃ and 60℃ yielded a low-level brown color and low turbidity, but the L values were high at 60℃ and 70℃. These results showed that 0.01% (v/v) mixing enzyme, i.e., pectinase and cellulose compounded at 60℃ for 60 min, must be used for the production of oriental melon concentrate.

Enzyme-sensing chitosan hydrogels.

We report on a chitosan hydrogel-based platform for the detection of enzymes, which is compatible with the implementation in infection-sensing wound dressings. Thin films of the established wound dressing biopolymer chitosan were functionalized with a fluorogenic substrate, which is released upon enzymatic degradation, resulting in a pronounced increase in fluorescence emission intensity. In this first model study, the fluorogenic substrate alanyl-alanyl-phenylalanine-7-amido-4-methylcoumarin (AAP-AMC) was covalently conjugated via amide bond formation to chitosan and was shown to facilitate the detection of the serine protease α-chymotrypsin. Systematic investigations established the dependence of hydrogel thickness and substrate loading on the hydrogel preparation conditions, as well as the dependence of the rate of the reaction on the initial enzyme concentration and the loading of AAP-AMC in the hydrogel. The initial release rate of the fluorophore 7-AMC was found to be linear with enzyme concentration and substrate loading and was independent of hydrogel thickness. Under optimized conditions the hydrogel reports the presence of α-chymotrypsin in <5 min with a limit of detection of ≤10 nM. This generic approach, which can be adapted to detect different kinds of enzymes by using appropriate fluorogenic or chromogenic substrates, is highly interesting for targeting the detection of specific pathogenic bacteria, e.g., in wound dressings.

Optimization of enzyme assisted extraction of Fructus Mori polysaccharides and its activities on antioxidant and alcohol dehydrogenase

In the present study, enzyme assisted extraction of Fructus Mori polysaccharides (FMPS) from F. mori using four kinds of enzymes and three compound enzymes were examined. Research found that glucose oxidase offered a better performance in enhancement of the extraction yields of FMPS, antioxidant and activate alcohol dehydrogenase activities. The glucose oxidase assisted extraction process was further optimized by using response surface method (RSM) to obtain maximum yield of crude FMPS. The results showed that optimized extraction conditions were ratio of enzyme amount 0.40%, enzyme treated time 38 min, treated temperature 58 °C and liquid-solid radio 11.0. Under these conditions, the mean experimental value of extraction yield (16.16 ± 0.14%) corresponded well with the predicted values and increased 160% than none enzyme treated ones. Pharmacological verification tests showed that F. mori crude polysaccharides had good antioxidant and activate alcohol dehydrogenase activities in vitro.

Enhancement of β-Glucan Content in the Cultivation of Cauliflower Mushroom (Sparassis latifolia) by Elicitation

The effectiveness of three kinds of enzymes (chitinase, β-glucuronidase, and lysing enzyme complex), employed as elicitors to enhance the β-glucan content in the sawdust-based cultivation of cauliflower mushroom (Sparassis latifolia), was examined. The elicitors were applied to the cauliflower mushroom after primordium formation, by spraying the enzyme solutions at three different levels on the sawdust-based medium. Mycelial growth was fully accomplished by the treatments, but the metabolic process during the growth of fruiting bodies was affected. The application of a lysing enzyme resulted in an increase in the β-glucan concentration by up to 31% compared to that of the control. However, the treatment resulted in a decrease in mushroom yield, which necessitated the need to evaluate its economic efficiency. Although we still need to develop a more efficient way for using elicitors to enhance functional metabolites in mushroom cultivation, the results indicate that the elicitation technique can be applied in the cultivation of medicinal/edible mushrooms.

An Important Regulation Factor in Depression: Indoleamine 2,3-dioxygenase

There are different theories and hypotheses related to the etiology of depression. Among them, cytokine hypothesis, hypothalamic-pituitary-adrenal axis hypothesis, monoamine hypothesis and neuroplasticity hypothesis are much more widely accepted. These hypotheses may discuss depression from different points, but they are all related to indoleamine 2, 3-dioxygenase (IDO). IDO is a kind of enzyme which can convert tryptophan (TRP), the precursor of serotonin to kynurenine (KYN). It can be activated by some proinflammatory cytokines. Once activated, more TRP would be siphoned from the formation of serotonin to KYN, which may cause a reduction in serotonin production. IDO can also be activated by stress hormones through tryptophan 2, 3-dioxygenase (TDO) or immune system. In addition, some downstream metabolites of KYN, such as kynurenic acid (KYNA), quinolinic acid (QUIN) and 3-hydroxykynurenine (3HKYN), may contribute to neuroplasticity, as they are neurotoxic or neuroprotective. IDO, the mutual regulation factor among these theories, may play an important role in the onset of depression.

Improving the enantioselectivity of an esterase toward (S)-ketoprofen ethyl ester through protein engineering

• Biochemical characteristics of Est25 were studied in various temperature, solvent and pH. • Mutated esterase (L255W) based on the modeled esterase structure has higher selectivity to (S)-ketoprofen ethyl ester than wild-type. • The addition of methanol or ethanol (as a solvent) led to drastic increases in the enantioselectivity of each enzyme. Esterases, enzymes that hydrolyze ester bonds, have been utilized to synthesize optically pure compounds like (S)-ketoprofen, which can be produced by the esterase-catalyzed hydrolysis of rac -ketoprofen ethyl ester. We previously reported a novel esterase, Est25, which was expressed in active form in Escherichia coli , and showed high hydrolyzing activities for various substrates. However, the enzyme did not show any preference for either of rac -ketoprofen ethyl ester. In this study, to improve the enantioselectivity of Est25, we used a protein engineering approach that involves building a homology model of Est25, library generation based on the model, screening for esterase activity, and screening for specificity toward (S)-ketoprofen ethyl ester. One variant, L255W was isolated showing significantly higher enantioselectivity than the wild-type enzyme. Enantioselectivity was further improved by adding one of the polar organic solvents, namely, ethanol and methanol. However, the mutant enzyme showed lower thermostability, higher sensitivity to pH, and lower resistance to polar solvents than Est25. The L255W mutation improves substrate specificity, but, at the same time, sacrifices structural stability. The approach used in this study is precise enough to engineer the substrate specificity of esterase, and general enough to be adapted to engineer other kinds of enzymes with a minimum amount of modifications.

효소를 이용한 아실화 반응의 최근 동향과 전망

가수분해 효소(혹은 아실전이효소)를 이용한 알콜과 아민의 아실반응은 에스터의 가수분해 반응(hydrolysis, deacylation)과 더불어 효소를 이용한 유기합성 반응에서 이미 잘 확립된 기술로서, 산업체에서 제약의 합성이나 고분자의 합성에서 널리 응용되고 있다. 이러한 효소를 이용한 아실화 반응은 주로 열역학적인 제한으로 인해 그동안 대부분이 주로 유기용매에서 이루어지고 있다. 최근 들어서, 수용액에서 아실화반응을 전이효소를 이용하여 효율적으로 할 수 있다는 보고와 함께 그 반응 기제에 대한 연구들이, X-ray 구조와 이러한 반응을 가능하게 하는 효소의 단백질 서열 비교 연구, 그리고 계산 화학에 의한 효소의 설계 연구등을 통해 새롭게 밝혀지고 있다. 본 총설에서는 효소를 이용한 아실화반응을 유기용매와 수용액에서의 수행함에 있어서 장단점을 비교해 보면서, 앞으로의 전망도 함께 제시하고자 한다. 특별히 다양한 천연물들의 구조 변화에 아실화 반응 생체촉매를 사용할 수 있는 가능성에 대해 살펴볼 것이다. Enzymatic acylations catalyzed by hydrolytic enzymes, along with enzymatic hydrolysis, are established reactions in the synthesis of fine chemicals such as chiral intermediates and polymerizations in the industry. Those reactions have been carried out mostly in organic media due to the thermodynamic limitations. Recently, there have been reports on enzymatic acylations in aqueous media. They have dealt with the elucidation of reaction mechanisms of hydrolases and acyl transferases based on their X-ray structures, homology comparison of the two kinds of enzymes, substrate engineering of acyl donors and computational design of acyl transferases for enzymatic acylations in aqueous media. Enzymatic acylations play an important role in the combinatorial synthesis of natural products such as polyketides and nonribosomal peptides. In this review, the historic developments of enzymatic acylations and industrial examples are described briefly. In addition, recent developments of enzymatic acylations in the modification of natural products and their prospects will be discussed.

Catechol Conjugates Are In Vivo Metabolites of Salicis cortex

After oral administration of 100 mg/kg b. w. (235.8 µmol/kg) salicortin to Wistar rats, peak serum concentrations of 1.43 mg/L (13.0 µM) catechol were detected after 0.5 h in addition to salicylic acid by HPLC-DAD after serum processing with β-glucuronidase and sulphatase. Both metabolites could also be detected in the serum of healthy volunteers following oral administration of a willow bark extract (Salicis cortex, Salix spec., Salicaceae) corresponding to 240 mg of salicin after processing with both enzymes. In humans, the cmax (1.46 mg/L, 13.3 µM) of catechol was reached after 1.2 h. The predominant phase-II metabolite in humans and rats was catechol sulphate, determined by HPLC analysis of serum samples processed with only one kind of enzyme. Without serum processing with glucuronidase and sulphatase, no unconjugated catechol could be detected in human and animal serum samples. As catechol is described as an anti-inflammatory compound, these results may contribute to the elucidation of the mechanism of the action of willow bark extract.

Development of Indole-3-Acetic Acid-Producing Escherichia coli by Functional Expression of IpdC, AspC, and Iad1

Biosynthesis of indole-3-acetic acid (IAA) via the indole-3-pyruvic acid pathway involves three kinds of enzymes; aminotransferase encoded by aspC, indole-3-pyruvic acid decarboxylase encoded by ipdC, and indole-3-acetic acid dehydrogenase encoded by iad1. The ipdC from Enterobacter cloacae ATCC 13047, aspC from Escherichia coli, and iad1 from Ustilago maydis were cloned and expressed under the control of the tac and sod promoters in E. coli. According to SDS-PAGE and enzyme activity, IpdC and Iad1 showed good expression under the control of P(tac), whereas AspC was efficiently expressed by P(sod) originating from Corynebacterium glutamicum. The activities of IpdC, AspC, and Iad1 from the crude extracts of recombinant E. coli Top 10 were 215.6, 5.7, and 272.1 nmol/min/mg-protein, respectively. The recombinant E. coli DH5α expressing IpdC, AspC, and Iad1 produced about 1.1 g/l of IAA and 0.13 g/l of tryptophol (TOL) after 48 h of cultivation in LB medium with 2 g/l tryptophan. To improve IAA production, a tnaA gene mediating indole formation from tryptophan was deleted. As a result, E. coli IAA68 with expression of the three genes produced 1.8 g/l of IAA, which is a 1.6- fold increase compared with wild-type DH5α harboring the same plasmids. Moreover, the complete conversion of tryptophan to IAA was achieved by E. coli IAA68. Finally, E. coli IAA68 produced 3.0 g/l of IAA after 24 h cultivation in LB medium supplemented with 4 g/l of tryptophan.

Oxalic Acid Enhances Remediation of Cr Contaminated Soil in Leersia Hexandra Swartz

This study examined the effect of oxalic acid on phytoremediation of Cr contaminated soil in Cr-hyperaccumulator Leersia hexandra Swartz (L. hexandra). The effects of 0, 40, 80, 120 mmol kg-1 oxalic acid (OA) on biomass, Cr accumulation and translocation of L. hexandra and four kinds of enzymes in 200,400 mg L-1 Cr contaminated soil planted L. hexandra were studied. The results showed that above-ground biomass was maximumly increased by 48.25% under OA treatment and OA also enhanced the plants ability to translocate Cr from roots to the harvestable aerial part which could contribute to phytoremediation. OA applied to soil planted L. hexandra with Cr stress maximumly increased dehydrogenase, sucrese, urease, peroxidase activities by 82.51%, 125.22%, 56.25%, 64.57% (p &lt; 0.01). These results suggest that OA is an important amendment which can enhance the remediation capability and soil activity of Cr contaminated soil in L. hexandra.

New Integration Technology on Preparation of Natural Seleniferous Rice Protein Peptide with Enzyme and Ultrasonic-Microwave Synergistic Technology

The natural seleniferous rice protein peptide was prepared by coupling with mixed-enzymes and ultrasonic-microwave synergistic technology in this paper. The kinds of enzyme was atteined first of all. Then the mathematical model of correlation among enzyme dosage, extraction temperature, extraction time and liquid-solid ratio were established by means of orthogonal experimental design. The optimal extraction conditions were determined as follows, alkali protease dosage 2.0%, extraction temperature 50°C, extraction time 40 min and liquid- solid ratio 7:1(m:g). Under such conditions, the extraction ratio was 72.2%, Se content was 6.88 μg/ml. The method could significantly improve the yield of natural seleniferous rice protein peptide and reduce the extraction time .The rich selenium rice protein peptide provides a very good source of selenium way in order to solve the lack of selenium source.

Research on the Technology and Mechanism of Inhibiting Stickies of Blanket by Enzyme Treatment

The stickies in pulp and paper machinery especially in the blankets will cause a lot of problems such as paper defects, increasing the time of machine shut down . Therefore, Inhibiting the Stickies of blanket is very important to regular production. In this study,we mainly studied on the inhibition of Stickies in the blanket with enzyme. The processed blanket was treated by several kinds of enzymes. The results showed that the optimum enzyme treatment conditions were obtained as followings:PH of 7, temperature of 50°C, 2×104U/g of cellulose enzyme, 2×103U/g of amylase and 104U/g of lipase. The blankets obtained better cleaning situation under this conditions.

ChemInform Abstract: Nanomaterials with Enzyme‐Like Characteristics (Nanozymes): Next‐Generation Artificial Enzymes

AbstractReview: 302 refs.

Response surface optimization of enzyme-assisted extraction polysaccharides from Dictyophora indusiata

An enzyme-assisted procedure for the extraction of the water-soluble polysaccharides from the stipe of Dictyophora indusiata was investigated using response surface methodology. The orthogonal array design was employed to optimize the concentration of three kinds of enzyme (cellulase, papain and pectolyase) and the optimal cellulose, papain and pectolyase concentration were 2.0% (wt.% of D. indusiata powder), 2.0% and 1.5%, respectively. And then the effect such as temperature, time and pH was studied based on a three-level three-factor Box-Behnken design. The optimized conditions were as follows: extraction temperature 52.5 °C, extraction time 105 min and pH 5.25. Under these conditions, the experimental yield of polysaccharides was 9.77±0.18%, which was well matched with the predictive yield of 9.87%. As it turned out, enzyme-assisted procedure was an effective method.

Application of enzyme in aqueous extraction of sesame oil

The oil recovery of the traditional process of extracting sesame oil by aqueous method could be improved by adding enzyme. Sesame oil was extracted under aqueous extraction conditions using three kinds of enzymes, which were papain, trypsin and cellulase. The optimal conditions were pH 7.0, 50 °C and extraction time 3 h with constant shaking at 80 rpm. The enzyme dosage and the enzyme proportion were researched by orthogonal experiment. The result indicated that the enzymes significantly improved the oil recovery. When the enzyme hydrolysis was performed with complex enzyme of papain 6,000 U, trypsin 400 U and cellulase 250 U/g oilseed, higher oil recovery (87.58 %) was achieved than the traditional aqueous extraction processing, and the oil was extremely fragrant. Moreover, the clear oil could fall directly from the centrifuge tube which greatly reduced the difficulty of separating oil.

Surface-Initiated, Reversible Polymerization from Surface-Tethered Oligonucleotides by Enzymatic Processes

Back and forth: Enzymatic, reversible polymerization on gold surfaces was efficiently carried out from surface-tethered self-priming oligodeoxynucleotides in a sequence-specific fashion by using two kinds of enzymes. Taq DNA polymerase, acting as a catalyst, facilitated DNA polymerization, and DNA restriction enzymes cut DNA polymers from the surface.

Nanomaterials with enzyme-like characteristics (nanozymes): next-generation artificial enzymes

Over the past few decades, researchers have established artificial enzymes as highly stable and low-cost alternatives to natural enzymes in a wide range of applications. A variety of materials including cyclodextrins, metal complexes, porphyrins, polymers, dendrimers and biomolecules have been extensively explored to mimic the structures and functions of naturally occurring enzymes. Recently, some nanomaterials have been found to exhibit unexpected enzyme-like activities, and great advances have been made in this area due to the tremendous progress in nano-research and the unique characteristics of nanomaterials. To highlight the progress in the field of nanomaterial-based artificial enzymes (nanozymes), this review discusses various nanomaterials that have been explored to mimic different kinds of enzymes. We cover their kinetics, mechanisms and applications in numerous fields, from biosensing and immunoassays, to stem cell growth and pollutant removal. We also summarize several approaches to tune the activities of nanozymes. Finally, we make comparisons between nanozymes and other catalytic materials (other artificial enzymes, natural enzymes, organic catalysts and nanomaterial-based catalysts) and address the current challenges and future directions (302 references).

Enzymatic Treatment Effects on Waste Activated Sludge from Pulp and Paper Industry

Sludge dewatering is a key part of sludge disposal since it can greatly reduce the volume of sludge and thus improve the treatment effect for handling and disposing. This study investigated the potential benefits of enzymatic pretreatment on activated sludge dewatering with four kinds of enzyme. Capillary suction time (CST) and the solid content after centrifugationwere used to evaluate sludge dewatering. A compression test of paper sludge obtained after treatment was carried out. Besides, some basic properties of activated sludge such as solid content, organic material content, ash content,MLSS,SV30,SVI.The results showed that enzyme additions did not enhanc the dewaterability of the biosolids samples ,but this positively affected filterability of the samples in the compression test. According to these results,enzyme product addition for biosolids samples seems a promising new method of enhancing the performance of mechanical dewatering units in the future.

Abnormalities of magnesium (Mg) metabolism and therapeutic significance of Mg administration in patients with metabolic syndrome, type 2 diabetes, heart failure and chronic hemodialysis

Magnesium (Mg) , one of the fundamental minerals acting the co-factor of about 300 kinds of enzymes and natural Ca channel blocker, plays an important role of cardiovascular, neurological, and metabolic functions in physiological, and pathophysiological conditions. Common abnormal Mg metabolism is an absolute or relative deficiency of Mg due to an attenuated Mg intake and an enhanced urinary Mg excretion, particularly in the metabolic syndrome (MetS) , type 2 diabetes (DM) , chronic heart failure (CHF) and hemodialysis (HD) patients with diabetes. It has been reported the Mg deficiency relating to enhanced risk of MetS and type 2 DM, and to fatal cardiac events in CHF and an atherosclerotic, vascular calcification in HD patients. On the otherhand, severe and fatal hypermagnesemia is very rare, except for the condition associated with high dose administration of Mg, renal failure and an abnormally enhanced Mg absorption from damaged intestine in the mesenteric ischemia/infarction, severe constipation or ileus. In this paper, we conduct to review and discuss the pathophysiological and pathogenetical role of the abnormal Mg metabolism focused on Mg deficiency, and the protective and therapeutic significance of Mg administration in the MetS, type 2 DM, CHF and diabetic HD patients.