Amino Acids Glu Research Articles

Comprehensive analysis of the effects of cooking conditions on the quality, sensory characteristics, and flavor profile of glutinous rice chicken, a Chinese traditional poultry meat product

This study investigated the effects of cooking conditions on cooking loss, texture, and sensory attributes of glutinous rice chicken (GRC), a popular Chinese poultry dish. We compared the nutritional and sensory profiles of GRC prepared under optimal conditions (GRC-OP) with those of a commercial product (CG). Cooking time, power, and pressure significantly affected the shear force, hardness, and sensory qualities of GRC. The optimal parameters were determined using an orthogonal design: 20 min cooking time, 1000 watts power, and 60 kPa pressure. Gas chromatography/mass spectrometry and E-nose analyses showed that GRC-OP had a volatile profile similar to that of CG but with higher levels of specific compounds, including heptanal, 2-heptenal, octanal, hexanol, octanol, and 1-nonen-4-ol. GRC-OP also exhibited superior umami, salty, and rich tastes, and higher amino acid content, particularly Asp, Glu, Thr, Ser, Ala, Val, Met, and Ile. These findings provide crucial data for optimizing the quality and nutritional value of GRC in the meat industry.

The dynamic changes and correlations between biochemical properties, flavor and microbial community during fermentation of asparagus by-products

Asparagus by-products are the promising resource that urgently need to be re-valorized. This study investigated the dynamic changes in physicochemical properties, organic acids, free amino acids, volatile flavor compounds, microbial succession, and their correlations during 7-day spontaneous fermentation of asparagus by-products. Dominant organic acids (lactic acid and acetic acid) and free amino acids (Ser, Glu, and Ala) increased with fermentation time, with lactic acid reaching 7.73 ± 0.05 mg/mL and Ser increasing 56-fold after 7 days. A total of 58 volatile flavor compounds were identified using headspace solid-phase microextraction-gas chromatography–mass spectrometry (HS-SPEM/GC–MS), with esters, alcohols and acids as the main volatile flavor compounds. Fourteen volatile flavor compounds had odor activity value >1. High-throughput sequencing showed Firmicutes and Proteobacteria as the main bacterial phyla, dominated by lactic acid bacteria (Levilactobacillus, Lactiplantibacillus, Weissella). Correlation analysis revealed that five bacterial genera (Levilactobacillus, Lactiplantibacillus, Enterobacter, Pediococcus and Acetobacter) were highly correlated with organic acids, free amino acids, and volatile flavor compounds, indicating their pivotal role in forming the characteristic flavor of fermented asparagus by-products (FAPS). This study provides new insights into the flavor and microbial profile of FAPS, offering a strategy for value-added processing and industrial production.

Specific inhibitory effects of exogenous d-Aspartate on the proliferation of intestinal epithelial cells

d-amino acids have been actively examined since improved analytical techniques revealed their presence in animal bodies. Although D-Asp was identified in mammals earlier than D-Ser, research on D-Asp has lagged behind that on D-Ser, mainly because the target protein of D-Asp remains unknown. To date, the only reported functions of D-Asp are its roles in reproduction and suggested neuromodulatory functions. Since d-amino acids are also present in food, it is important to clarify their effects on gastrointestinal epithelial cells, which are always contacted after ingestion. Therefore, the present study examined the effects of d-amino acids on gastrointestinal tract basal cells. The effects of 11 types of amino acids (Ala, Arg, Asn, Asp, Gln, Glu, Leu, Lys, Pro, Ser, and Val) on the proliferation of three types of gastrointestinal epithelial cells (HGC-27, IEC-6, and Caco-2) were assessed. Although the proliferation of HGC-27 and Caco-2 was not affected by any of the 11 types of L- and d-amino acids, D-Asp inhibited the proliferation of IEC-6, derived from small intestinal epithelial cells, in concentration- and exposure time-dependent manners. The present study also examined uptake transporters, metabolic enzymes, and insulin signaling pathways; however, the mechanisms underlying the inhibitory effects of D-Asp on the proliferation of IEC-6 were not elucidated. A more detailed understanding of these mechanisms may lead to the development of pharmaceuticals as main drugs or formulation materials. Further studies are warranted on the physiological effects of d-amino acids, including D-Asp.

Effects of Substituting Tenebrio molitor and Elodea nuttallii as Feed on Growth, Flesh Quality and Intestinal Microbiota of Red Swamp Crayfish (Procambarus clarkii).

This study aimed to evaluate the impact of substituting a portion of feed with Tenebrio molitor (TM) and Elodea nuttallii (EN) on crayfish culture. A total of 270 crayfish (5.1 ± 0.4 g) were fed three different diet combinations (A: 100% feed; B: 80% feed + 10% TM + 10% EN; C: 75% feed + 15% TM + 10% EN) for 12 weeks. The findings demonstrated that group C had an important beneficial impact on the growth performance of crayfish. This was evidenced by a rise in digestive enzyme activity (trypsin, lipase, and cellulase) in the intestinal and hepatopancreas, as well as an upregulation in the expression of growth-related genes (ghsr, igfbp7, mhc, mlc1, mef2, and pax7) in the muscle. Furthermore, the assessment of the flesh quality of crayfish muscle in group C was conducted. The findings indicated a significant increase (p < 0.05) in the energy value (moisture, crude protein, and crude lipid) within the muscle. The levels of delicious amino acids (Glu, Ala, Ser, Gly, and Tyr) and polyunsaturated fatty acids (ARA, DHA) were enhanced, resulting in an improved nutritional profile and flavor of the muscle while maintaining the Σn-3/Σn-6 ratio. The remodeling of the intestinal microbiota (abundance of Proteobacteria and ratio of Firmicutes/Bacteroidota bacteria) also revealed improved growth performance. Additional research is necessary to ascertain whether excessive use of TM or EN feed substitution can have negative effects on crayfish culture.

Mechanism Involved in Polyvinyl Chloride Nanoplastics Induced Anaerobic Granular Sludge Disintegration: Microbial Interaction Energy, EPS Molecular Structure, and Metabolism Functions.

Nanoplastics (NPs) are emerging pollutants and have been reported to cause the disintegration of anaerobic granular sludge (AnGS). However, the mechanism involved in AnGS disintegration was not clear. In this study, polyvinyl chloride nanoplastics (PVC-NPs) were chosen as target NPs and their long-term impact on AnGS structure was investigated. Results showed that increasing PVC-NPs concentration resulted in the inhibition of acetoclastic methanogens, syntrophic propionate, and butyrate degradation, as well as AnGS disintegration. At the presence of 50 μg·L-1 PVC-NPs, the hydrophobic interaction was weakened with a higher energy barrier due to the relatively higher hydrophilic functional groups in extracellular polymeric substances (EPS). PVC-NPs-induced ROS inhibited quorum sensing, significantly downregulated hydrophobic amino acid synthesis, whereas it highly upregulated the genes related to the synthesis of four hydrophilic amino acids (Cys, Glu, Gly, and Lys), resulting in a higher hydrophily degree of protein secondary structure in EPS. The differential expression of genes involved in EPS biosynthesis and the resulting protein secondary structure contributed to the greater hydrophilic interaction, reducing microbial aggregation ability. The findings provided new insight into the long-term impact of PVC-NPs on AnGS when treating wastewater containing NPs and filled the knowledge gap on the mechanism involved in AnGS disintegration by PVC-NPs.

Identification of RESP18 Gene Mutations Linked to Hereditary Non-Syndromic Cleft Lip and Palate in a Southern Chinese Family.

BACKGROUND Non-syndromic cleft lip with cleft palate (NSCLP) is one of the most common congenital birth defects worldwide; it causes lifelong problems and imposes burdens on patients and their families. This study aimed to describe the genomic analysis and identification of de novo regulated endocrine-specific protein 18 (RESP18) rs2385404 and rs2385405 gene polymorphisms associated with NSCLP in a southern Chinese family and to improve prevention, treatment, and prognosis of NSCLP. MATERIAL AND METHODS We performed a genome-wide association study (GWAS) to investigate the association of NSCLP phenotype with gene mutation. We investigated a 5-persons NSCLP family to screen the genetic variation of Han nationality in southern Chinese. Whole-genome sequencing (WGS) was used to detect all candidate genetic variants, and whole-exome sequencing (WES) was implemented to further verify mutations. The Clinical Variation Data Base (ClinVar) was employed for screening gene mutations. Finally, Sanger sequencing was applied to verify gene variations. RESULTS The combined analysis of WGS, WES, and ClinVar showed that a total of 9 variation positions overlapped among the 3 study cohorts. Sanger sequencing verified Glu amino acid variation in 2 mutation sites (rs2385404, rs2385405) from the RESP18 gene, which caused abnormal RESP18 function and was associated with hereditary NSCLP. CONCLUSIONS The combined genomic results showed that 2 mutations (rs2385404 and rs2385405) of the RESP18 gene were related to NSCLP in the family. The RESP18 gene may play an important role in the etiology and pathogenesis of cleft lip and palate.

Enhancing bread anti-staling with glucose-derived Maillard reaction products: In-depth analysis of starches, gluten networks, and moisture status

In this study, six types of amino acids (Ala, Phe, Glu, Gly, Ser, and Lys) were combined with glucose to produce Maillard reaction products (MRPs) named G-Ala, G-Phe, G-Glu, G-Gly, G-Ser and G-Lys. The effect of MRPs on bread staling was evaluated through texture and sensory analyses during storage. Furthermore, the study comprehensively analyzed the anti-staling mechanisms of MRPs by examining moisture content, starches, and gluten network changes. The results indicated that G-Gly and G-Glu delayed bread staling, with G-Gly showing the most significant effect. Compared with control, the staling rate and starch crystallinity of G-Gly bread decreased by 24.07% and 7.70%, respectively. Moreover, G-Gly increased the moisture content (3.48%), weakly bound water mobility (0.77%), and α-helix content (1.00%) of bread. Component identification and partial least squares regression further confirmed the aldonic acid, heterocyclic acids and heterocyclic ketones in MRPs inhibit water evaporation, gluten network loosening, and starch degradation, thereby delaying bread staling.

Calcium-chelating peptides from rabbit bone collagen: characterization, identification and mechanism elucidation

This study aimed to characterize and identify calcium-chelating peptides from rabbit bone collagen and explore the underlying chelating mechanism. Collagen peptides and calcium were extracted from rabbit bone by instant ejection steam explosion (ICSE) combined with enzymatic hydrolysis, followed by chelation reaction to prepare rabbit bone peptide-calcium chelate (RBCP-Ca). The chelating sites were further analyzed by liquid chromatography-tandem mass (LC-MS/MS) spectrometry while the chelating mechanism and binding modes were investigated. The structural characterization revealed that RBCP successfully chelated with calcium ions. Furthermore, LC-MS/MS analysis indicated that the binding sites included both acidic amino acids (Asp and Glu) and basic amino acids (Lys and Arg). Interestingly, three binding modes, namely Inter-Linking, Loop-Linking and Mono-Linking were for the first time found, while Inter-Linking mode accounted for the highest proportion (75.1 %), suggesting that chelation of calcium ions frequently occurred between two peptides. Overall, this study provides a theoretical basis for the elucidation of chelation mechanism of calcium-chelating peptides.

Physiological and metabolic analyses reveal the proline-mediated flowering delay mechanism in Prunus persica.

Peaches are susceptible to various environmental stresses. Particularly in late spring, freezing temperatures can damage peaches and consequently, affect their productivity. Therefore, flowering delay is a prominent strategy for avoiding spring frost damage. Our previous study confirmed that treatment with 5% sodium alginate and 100 mM CaCl2 (5AG) to avoid frost damage during the blooming stage delays flowering. To reveal the flowering delay mechanism of peaches, this study systematically analyzed the modification of amino acid profiles in control and 5AG-treated peach plants at different day intervals. Our findings indicate that arginine (Arg), glutamate (Glu), and proline (Pro) levels differed between the control and 5AG-treated peach shoots throughout the phenological development of flower buds. Furthermore, two amino acids (Arg and Glu) are involved in the Pro pathway. Thus, using a computational metabolomics method, Pro biosynthesis and its characteristics, gene ontology, gene synteny, cis-regulatory elements, and gene organizations were examined to decipher the involvement of Pro metabolism in peach flowering delay. In addition, qRT-PCR analysis revealed the transcriptional regulation of Pro-related and flowering-responsive genes and their role in flowering delay. Overall, this pilot study provides new insights into the role of Pro in the flowering delay mechanisms in Prunus persica through 5AG treatment.

Analysis of carcass traits, meat quality, amino acid and fatty acid profiles between different duck lines

To investigate the effect of genetic selection on meat quality in ducks, twenty of each fast growth ducks (LCA) and slow growth ducks (LCC) selected from F6 generation of Cherry Valley ducks (♂) x Liancheng white ducks (♀) were analyzed for carcass characteristics, meat quality (physicochemical and textural characteristics), amino acid and fatty acid profiles at 7 wk. Results showed that live body weight, slaughter weight, eviscerated yield and abdominal fat percentage of LCA were significantly higher than those in LCC ducks (P < 0.01). Moreover, the average area and diameter of myofiber were larger in LCA than LCC ducks (P < 0.01). The breast and thigh muscles of LCA exhibited significantly lower water holding capacity and thermal loss compared with LCC ducks (P < 0.01). In addition, the content of nonessential amino acids (Glu, Asp, and Arg) in breast muscles and Asp, Ser, Thr, and Met in thigh muscles was higher in LCC than LCA ducks (P < 0.05). The proportion of polyunsaturated fatty acids (PUFA) in breast muscles of LCC was higher than LCA ducks (P < 0.05). However, the content of saturated fatty acids (SFA) in breast and thigh muscles of LCA was higher compared with LCC ducks (P < 0.05). The proportion of monounsaturated fatty acids (MUFA) in thigh muscles was significantly higher in LCC compared with LCA ducks (P < 0.01). Finally, multiple traits were evaluated by applying principal component analysis (PCA) and the results indicated that PUFA and SFA in breast muscles of LCA played important roles in meat quality, followed by Warner-Bratzler shear force (WBSF) and MUFA. However, water holding capacity (WHC) had a dominant effect in meat quality of thigh muscles in both LCA and LCC ducks.

Constant-pH Simulations with the Polarizable Atomic Multipole AMOEBA Force Field.

Accurately predicting protein behavior across diverse pH environments remains a significant challenge in biomolecular simulations. Existing constant-pH molecular dynamics (CpHMD) algorithms are limited to fixed-charge force fields, hindering their application to biomolecular systems described by permanent atomic multipoles or induced dipoles. This work overcomes these limitations by introducing the first polarizable CpHMD algorithm in the context of the Atomic Multipole Optimized Energetics for Biomolecular Applications (AMOEBA) force field. Additionally, our implementation in the open-source Force Field X (FFX) software has the unique ability to handle titration state changes for crystalline systems including flexible support for all 230 space groups. The evaluation of constant-pH molecular dynamics (CpHMD) with the AMOEBA force field was performed on 11 crystalline peptide systems that span the titrating amino acids (Asp, Glu, His, Lys, and Cys). Titration states were correctly predicted for 15 out of the 16 amino acids present in the 11 systems, including for the coordination of Zn2+ by cysteines. The lone exception was for a HIS-ALA peptide where CpHMD predicted both neutral histidine tautomers to be equally populated, whereas the experimental model did not consider multiple conformers and diffraction data are unavailable for rerefinement. This work demonstrates the promise polarizable CpHMD simulations for pKa predictions, the study of biochemical mechanisms such as the catalytic triad of proteases, and for improved protein-ligand binding affinity accuracy in the context of pharmaceutical lead optimization.

Effects of the kinetic pattern of dietary glucose release on nitrogen utilization, the portal amino acid profile, and nutrient transporter expression in intestinal enterocytes in piglets

BackgroundPromoting the synchronization of glucose and amino acid release in the digestive tract of pigs could effectively improve dietary nitrogen utilization. The rational allocation of dietary starch sources and the exploration of appropriate dietary glucose release kinetics may promote the dynamic balance of dietary glucose and amino acid supplies. However, research on the effects of diets with different glucose release kinetic profiles on amino acid absorption and portal amino acid appearance in piglets is limited. This study aimed to investigate the effects of the kinetic pattern of dietary glucose release on nitrogen utilization, the portal amino acid profile, and nutrient transporter expression in intestinal enterocytes in piglets.MethodsSixty-four barrows (15.00 ± 1.12 kg) were randomly allotted to 4 groups and fed diets formulated with starch from corn, corn/barley, corn/sorghum, or corn/cassava combinations (diets were coded A, B, C, or D respectively). Protein retention, the concentrations of portal amino acid and glucose, and the relative expression of amino acid and glucose transporter mRNAs were investigated. In vitro digestion was used to compare the dietary glucose release profiles.ResultsFour piglet diets with different glucose release kinetics were constructed by adjusting starch sources. The in vivo appearance dynamics of portal glucose were consistent with those of in vitro dietary glucose release kinetics. Total nitrogen excretion was reduced in the piglets in group B, while apparent nitrogen digestibility and nitrogen retention increased (P < 0.05). Regardless of the time (2 h or 4 h after morning feeding), the portal total free amino acids content and contents of some individual amino acids (Thr, Glu, Gly, Ala, and Ile) of the piglets in group B were significantly higher than those in groups A, C, and D (P < 0.05). Cluster analysis showed that different glucose release kinetic patterns resulted in different portal amino acid patterns in piglets, which decreased gradually with the extension of feeding time. The portal His/Phe, Pro/Glu, Leu/Val, Lys/Met, Tyr/Ile and Ala/Gly appeared higher similarity among the diet treatments. In the anterior jejunum, the glucose transporter SGLT1 was significantly positively correlated with the amino acid transporters B0AT1, EAAC1, and CAT1.ConclusionsRational allocation of starch resources could regulate dietary glucose release kinetics. In the present study, group B (corn/barley) diet exhibited a better glucose release kinetic pattern than the other groups, which could affect the portal amino acid contents and patterns by regulating the expression of amino acid transporters in the small intestine, thereby promoting nitrogen deposition in the body, and improving the utilization efficiency of dietary nitrogen.

Shrimp Cultured in Low-Salt Saline-Alkali Water has a Better Amino Acid Nutrition and Umami─Comparison of Flavors between Saline-Alkali Water- and Seawater-Cultured Litopenaeus vannamei.

The advantages of Litopenaeus vannamei farming in saline-alkali water have gradually attracted attention, but few studies have focused on its flavor. In this study, L. vannamei cultured in saline-alkali water (SS) and ordinary seawater (CS) (both have a breeding time of 120 days) were selected for analysis (n = 5). High-performance liquid chromatography (HPLC) was used to measure free amino acids and flavoring nucleotides in the muscles of L. vannamei, while the taste activity value (TAV) and equivalent umami concentration (EUC) were used to analyze the degree of umami. The total essential amino acids (TEAA) in the SS group were 238.41 ± 46.24 mg/mL, significantly higher than that in the CS group (107.06 ± 15.65 mg/mL). The total amount of flavor nucleotides in the SS group was 2948.51 ± 233.66 μg/mL, significantly higher than those in the CS group (2530.37 ± 114.67 μg/mL). The content and TAV of some free amino acids (Glu, Cys-s) in the SS group were significantly higher. Meanwhile, due to the significant increase in IMP, the synergistic effect of free amino acids and flavored nucleotides leads to higher EUC. The significant separation of SS and CS samples in principal component analysis (PCA) indicates a significant difference between the two groups. Our results indicate that shrimp cultured in saline-alkali water has a stronger umami. This study enriches the basic theories related to the flavor of salt-alkali water crustaceans.

Dual enhancement effects of different yeast extract on gel properties and saltiness perception of low-salt surimi gel from silver carp

This study investigated the dual enhancement effect of five yeast extracts (YE) on gel properties and saltiness perception of low-salt (1% NaCl) surimi gels. The addition of YE not only pronouncedly enhanced the gel strength, texture properties (hardness, cohesiveness and chewiness) and elasticity of low-salt surimi gel (P < 0.05), but also increased the gelation rate of surimi during kamaboko stage. When YE was added, the water holding capacity of surimi gels increased, accompanied by decreased water fluidity, and composite gels exhibited a relatively dense and ordered microstructure. Electronic tongue analysis indicated that YE addition enhanced umami and saltiness, and decreased the sour and bitterness characteristic values (P < 0.05). Besides, sensory evaluation showed that YE increased the texture, saltiness, umami and smell score of low-salt surimi gel (P < 0.05), and the saltiness perception of low-salt surimi gel added with YE1 and YE2 was similar to normal-salt surimi gel (2% NaCl), which was consistent with the result of electronic tongue. The correlation analysis result revealed that the enhancement of gel properties of surimi may be attributed to the charged amino acids (Arg, Lys, His, Glu and Asp) in YE, and the umami substances (Glu, Asp, IMP and GMP) in YE could not only improve the umami taste, but also enhance the saltiness perception of low-salt surimi gel. Overall, YE had the dual effect of remarkably improving the gel properties and enhancing saltiness perception of low-salt surimi gel, providing a salt reduction effect, with YE2 being the best.

Replacement of fish meal with cottonseed protein concentrate in Chinese mitten crab (Eriocheir sinensis): Nutrient digestibility, growth performance, free amino acid profile, and expression of genes related to nutrient metabolism

This study aimed to investigate the application of cottonseed protein concentrate (CPC) in Chinese mitten crabs (Eriocheir sinensis). First, the apparent digestibility coefficient (ADC) of CPC, fish meal and soybean meal were compared in crabs (21.72 ± 0.33 g). The protein ADC of CPC was 90.42%, which was significantly higher than that of soybean meal (83.16%) (P < 0.05). The ADC of Phe, Cys and Glu of CPC were significantly higher than those of fish meal, while the ADC of Ile, Leu, Lys, Met, Thr and Ala of CPC were significantly lower (P < 0.05). Second, we investigated the effects of fish meal substitution by CPC on growth performance, free amino acid profile, and expression of genes related to nutrient metabolism in crabs. Six diets were formulated by replacing 0%, 15%, 30%, 45%, 60% and 75% fish meal with CPC, namely FM, CPC15, CPC30, CPC45, CPC60, and CPC75. A total of 630 crabs (1.68 ± 0.00 g) were randomly divided into 18 tanks (3 tanks per group) and fed 3 times daily for 9 weeks. Results showed that CPC75 group significantly reduced growth performance, feed conversion efficiency, and free Ile, Leu, Lys, Met, and Thr contents in muscle (P < 0.05). The contents of free amino acids (Arg, His, Ile, Leu, Lys, Met, Phe, Thr, Val, Ala, Cys, Glu, Gly, Ser and Tyr) in hepatopancreas decreased linearly with the increase of dietary CPC level (P < 0.05). The substitution of more than 45% fish meal with CPC significantly decreased the concentration of delicious amino acids (Ala, Glu and Gly) in hepatopancreas (P < 0.05), which might adversely affect crab flavor. The expression of genes related to antioxidant capacity, protein transport, TOR pathway and lipid metabolism was significantly downregulated by increasing dietary CPC level (P < 0.05). In conclusion, based on the quadratic regression analysis of FCR and PER, the optimal replacement levels of fish meal with CPC in crab diet containing 35% fish meal were 32.36% and 35.38%, respectively. It is recommended that Ile, Leu and Thr be supplemented in addition to Met and Lys in the application of CPC.

Exfoliation of an extruded Mg-4Li-1Ca alloy in presence of glucose and bovine serum albumin

Exfoliation corrosion (EFC) on extruded Mg-4Li-1Ca alloys as bone implant materials has not been reported. This study aimed to elucidate the degradation mechanism of a corrosion type-exfoliation occurred on an extruded Mg-4Li-1Ca alloy under the interaction of glucose (Glu) and bovine serum albumin (BSA) in Hank’s solution. The alloy microstructure, chemical composition, texture, stress distribution and Volta potential maps were characterized using metallographic microscopy, scanning electron microscopy and electron backscattered diffraction, and scanning Kelvin Probe. The alloy corrosion behavior was investigated via electrochemical testing and hydrogen evolution rate methods. X-ray diffraction, Fourier transform infrared spectrometry, X-ray photoelectron spectrometer, and fluorescence microscopy were used to analyze the corrosion products and the adsorption of the organic molecules. The experimental results indicated that the anodic second phase (Mg2Ca) were distributed in lamellar and rod-like patterns along the extrusion direction of the alloy, a lower Volta potential for Mg2Ca, texture and residual stresses also promote EFC. An increase in Glu concentration exacerbated the EFC, whereas BSA inhibited the EFC of the alloy. Higher Glu concentrations in BSA in turn inhibited EFC since Glu can complex with amino acids in proteins to form Glu-amino acid amides, which promoted protein adsorption and thereby forming a dense protective film on the alloy surface. The preferential dissolution of the Mg2Ca phase particles led to the complexation and adsorption of Glu and protein. This study enriches the understanding of the corrosion types in biomedical Mg-4Li-1Ca alloy and paving the way for enhancing the EFC resistance of the alloy.

The regulation of organic molecules to the morphology and corrosion protection ability of CaCO3 coating on biomedical MgZnCa alloy

A controllable corrosion rate is an ideal condition for magnesium (Mg) alloy as biodegradable metallic materials. Calcium carbonate (CaCO3) coating has been proven to possess a robust anti-corrosion property for Mg alloy. To further regulate the morphology and corrosion protection ability of the CaCO3 coating, in current study, different organic molecules, including amino acids (Tyr and Glu), amine (DOPA), proteins (COL and BSA) and peptide (CPP), were added into the coating formation electrolyte, affecting the morphology, polymorph composition, and the crystal size distribution of precipitated CaCO3. The results revealed that Tyr exhibited little effect on the polymorph composition of the CaCO3-based coating, while Glu, DOPA, COL and BSA generally promoted the formation of vaterite but inhibited the formation of rod-like aragonite precipitates and calcite in the coatings. In contrast, CPP suppressed the precipitation of CaCO3 crystals because of its high affinity to Ca2+ ions. The addition of those organics reduced the size of calcite crystals. Consequently, the organic molecules mediated CaCO3-based coatings showed better compactness and homogeneity, which maintained the strong adhesion strength of the coatings to the substrate and further enhanced the corrosion protection abilities of the coating for the substrate. The results of the study pave the way for the development of CaCO3-based coatings with advanced properties for Mg alloys as biomedical materials.

Targeted delivery of liposomal Ribociclib to SLC7A5 transporters in breast cancer cells.

This study aimed to prepare SLC7A5 transporters targeted liposomes of Ribociclib (RB) by stear(o)yl conjugation of Phe, Asp, Glu amino acids to liposomes as targeting moieties. The liposomes were optimized for their formulations. Cell analysis on two cell lines of MCF-7 and NIH-3T3 were done including; cell viability test by MTT assay, cellular uptake, and cell cycle arrest by flow cytometry. The optimal liposomes showed the particle size of 123.6 ± 1.3 nm, drug loading efficiency and release efficiency of 83.87% ± 1.33% and 60.55% ± 0.46%, respectively. The RB loaded liposomes showed no hemolysis activity. Targeted liposomes increased cytotoxicity on MCF-7 cells more significantly than NIH-3T3 cells. Cell flow cytometry indicated that targeted liposomes uptake was superior to plain (non-targted) liposomes and free drug. Free drug and RB-loaded liposomes interrupted cell cycle in G1. However, amino acid-targeted liposomes arrested cells more than the free drug at this stage. Targeted liposomes reduced cell cycle with more interruption in the G2/M phase compared to the negative control.

Identification and stability analysis of potential ADP-ribose modification sites on vascular endothelial growth factor (VEGF) through molecular dynamics simulation

Post-translational modifications (PTMs) are crucial covalent processes that alter protein properties, achieved through proteolytic cleavage or addition of modifying groups like acetyl, phosphoryl, glycosyl, or methyl to amino acids. ADP-ribosylation is a reversible post-translational modification, where ADP-ribose units are covalently attached to target protein side chains. Vascular endothelial growth factor (VEGF) is a potent angiogenic factor that plays a key role in physiological and pathological conditions. Studies have reported that ADP-ribosylation affects VEGF's ability to bind to VEGF receptors, impacting angiogenesis signalling. However, the specific amino acid undergoing ADP-ribosylation on VEGF remained unknown. To understand the mechanism of ADP-ribose addition to VEGF, an in silico study was designed. The study initially checked for the presence of any conserved motif where ADP-ribosylation could potentially occur and identified the presence of the EIE motif in VEGF, a probable site for ADP-ribosylation for many proteins. Subsequently, the amino acids near this motif were selected and their structural properties were analyzed. Surface-exposed amino acids were chosen, and ADP-ribose was then added to their side chains. The results revealed that the amino acids ASP (67) and GLU (70) underwent glycosidic linkage with ADP-ribose, indicating that they are the most probable modification sites. Subsequently, Molecular dynamic simulation analysis such as RMSD, RMSF, Rg, PCA, and FEL, along with MM-PBSA binding free energy calculations were performed to understand the stability of the VEGF-ADP-ribose complexes. The analysis revealed that amino acid at position 67 (ASP67) is the most probable site for ADP-ribosylation in VEGF. Communicated by Ramaswamy H. Sarma

Seasonal effect on the amino acid and fatty acid profiles of Ulva spp. collected from Sepanjang Beach, Yogyakarta, Indonesia

In this study, nutritional composition including amino acid and fatty acid profiles of Ulva spp. from Sepanjang beach, Yogyakarta, Indonesia collected on different seasons were investigated. The result showed that the dry season had a higher level of total amino acid than the rainy season. The presence of complete essential amino acid (EAA) in the rainy and dry seasons was discovered, accounting for 35.88% and 37.51% of the total amino acid, respectively. Flavour amino acids (Glu, Asp, Ala) were prominent in Ulva spp. and reached up to 34.30% of the total amino acid for both seasons. The ratio of essential to non-essential amino acids of Ulva spp. from the dry season was greater and substantially different (p < 0.05) than that of the rainy season. Meanwhile, the sulfur-containing amino acid concentration during the dry season declined to 2.69% from 6.59% of total amino acid in the rainy. As demonstrated by the assessment of fatty acids, saturated fatty acids (SFAs) were more prevalent in Ulva spp. over the dry season, whereas polyunsaturated fatty acids (PUFAs) dominated during the rainy season. Ulva spp. harvested in the dry season had higher polyunsaturated fatty acid (PUFA) content than that of the rainy season. Eicosapentaenoic acid (EPA) was only detected in Ulva spp. from the rainy season, whereas DHA and AA were not detected in both samples. Generally, the amino acid and fatty acid profiles of Ulva spp. correlate with seasonal variations. Overall, the present investigation demonstrates the prospects of under-exploited green seaweed resources from Indonesia to be applied in food industries.