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Fulltext Structural and functional analyses of Burkholderia pseudomallei BPSL1038 reveal a Cas-2/VapD nuclease sub-family

Shaibullah S, Shuhaimi N, Ker DS, Mohd-Sharif N, Ho KL, Teh AH, et al.

Commun Biol, 2023 Sep 08;6(1):920.
PMID: 37684342 DOI: 10.1038/s42003-023-05265-4

Burkholderia pseudomallei is a highly versatile pathogen with ~25% of its genome annotated to encode hypothetical proteins. One such hypothetical protein, BPSL1038, is conserved across seven bacterial genera and 654 Burkholderia spp. Here, we present a 1.55 Å resolution crystal structure of BPSL1038. The overall structure folded into a modified βαββαβα ferredoxin fold similar to known Cas2 nucleases. The Cas2 equivalent catalytic aspartate (D11) pairs are conserved in BPSL1038 although B. pseudomallei has no known CRISPR associated system. Functional analysis revealed that BPSL1038 is a nuclease with endonuclease activity towards double-stranded DNA. The DNase activity is divalent ion independent and optimum at pH 6. The concentration of monovalent ions (Na+ and K+) is crucial for nuclease activity. An active site with a unique D11(X20)SST motif was identified and proposed for BPSL1038 and its orthologs. Structure modelling indicates the catalytic role of the D11(X20)SST motif and that the arginine residues R10 and R30 may interact with the nucleic acid backbone. The structural similarity of BPSL1038 to Cas2 proteins suggests that BPSL1038 may represent a sub-family of nucleases that share a common ancestor with Cas2.

Matched MeSH terms: Aspartic Acid
An improved hybrid of particle swarm optimization and the gravitational search algorithm to produce a kinetic parameter estimation of aspartate biochemical pathways

Ismail AM, Mohamad MS, Abdul Majid H, Abas KH, Deris S, Zaki N, et al.

Biosystems, 2017 Dec;162:81-89.
PMID: 28951204 DOI: 10.1016/j.biosystems.2017.09.013

Mathematical modelling is fundamental to understand the dynamic behavior and regulation of the biochemical metabolisms and pathways that are found in biological systems. Pathways are used to describe complex processes that involve many parameters. It is important to have an accurate and complete set of parameters that describe the characteristics of a given model. However, measuring these parameters is typically difficult and even impossible in some cases. Furthermore, the experimental data are often incomplete and also suffer from experimental noise. These shortcomings make it challenging to identify the best-fit parameters that can represent the actual biological processes involved in biological systems. Computational approaches are required to estimate these parameters. The estimation is converted into multimodal optimization problems that require a global optimization algorithm that can avoid local solutions. These local solutions can lead to a bad fit when calibrating with a model. Although the model itself can potentially match a set of experimental data, a high-performance estimation algorithm is required to improve the quality of the solutions. This paper describes an improved hybrid of particle swarm optimization and the gravitational search algorithm (IPSOGSA) to improve the efficiency of a global optimum (the best set of kinetic parameter values) search. The findings suggest that the proposed algorithm is capable of narrowing down the search space by exploiting the feasible solution areas. Hence, the proposed algorithm is able to achieve a near-optimal set of parameters at a fast convergence speed. The proposed algorithm was tested and evaluated based on two aspartate pathways that were obtained from the BioModels Database. The results show that the proposed algorithm outperformed other standard optimization algorithms in terms of accuracy and near-optimal kinetic parameter estimation. Nevertheless, the proposed algorithm is only expected to work well in small scale systems. In addition, the results of this study can be used to estimate kinetic parameter values in the stage of model selection for different experimental conditions.

Matched MeSH terms: Aspartic Acid/metabolism*
Lactobacillus Spp.-Enhanced Memory is Strain-Dependent and Associated, in Part, with Amyloidogenic and anti-Oxidant/Oxidative Stress Interplay in Amyloid Beta Precursor Protein Transgenic Mice

Ahmad Alwi NA, Lim SM, Mani V, Ramasamy K

J Diet Suppl, 2023;20(5):717-734.
PMID: 35876040 DOI: 10.1080/19390211.2022.2103608

This study explored mechanisms underpinning enhanced memory in amyloid precursor protein (APP) transgenic mice (male; 10-12 months; n = 6/group) supplemented with Lactobacillus plantarum LAB12 (LAB12)/Lactobacillus casei Shirota (LcS). Morris Water Maze test was performed before brains were harvested for gene expression and biochemical studies. LAB-supplemented mice exhibited reduced escape latency and distance but significant increased time spent in platform zone. This was associated with downregulated beta-site APP cleaving enzyme-1 (BACE1) mRNA and significant reduced nitric oxide in brains. LAB12 also significantly increased glutathione. The LAB-enhanced memory is strain-dependent and could be mediated, in part, through amyloidogenic pathway and anti-oxidant/oxidative stress interplay.

Matched MeSH terms: Aspartic Acid Endopeptidases/genetics; Aspartic Acid Endopeptidases/metabolism
Enhancement of β-secretase inhibition and antioxidant activities of tempeh, a fermented soybean cake through enrichment of bioactive aglycones

Ahmad A, Ramasamy K, Majeed AB, Mani V

Pharm Biol, 2015 May;53(5):758-66.
PMID: 25756802 DOI: 10.3109/13880209.2014.942791

Soybean and its fermented products are the most common source of isoflavones in human food.

Matched MeSH terms: Aspartic Acid Endopeptidases/antagonists & inhibitors*; Aspartic Acid Endopeptidases/metabolism
Neurometabolites Alteration in the Acute Phase of Mild Traumatic Brain Injury (mTBI): An In Vivo Proton Magnetic Resonance Spectroscopy (1H-MRS) Study

Veeramuthu V, Seow P, Narayanan V, Wong JHD, Tan LK, Hernowo AT, et al.

Acad Radiol, 2018 09;25(9):1167-1177.
PMID: 29449141 DOI: 10.1016/j.acra.2018.01.005

RATIONALE AND OBJECTIVES: Magnetic resonance spectroscopy is a noninvasive imaging technique that allows for reliable assessment of microscopic changes in brain cytoarchitecture, neuronal injuries, and neurochemical changes resultant from traumatic insults. We aimed to evaluate the acute alteration of neurometabolites in complicated and uncomplicated mild traumatic brain injury (mTBI) patients in comparison to control subjects using proton magnetic resonance spectroscopy (1H magnetic resonance spectroscopy).
MATERIAL AND METHODS: Forty-eight subjects (23 complicated mTBI [cmTBI] patients, 12 uncomplicated mTBI [umTBI] patients, and 13 controls) underwent magnetic resonance imaging scan with additional single voxel spectroscopy sequence. Magnetic resonance imaging scans for patients were done at an average of 10 hours (standard deviation 4.26) post injury. The single voxel spectroscopy adjacent to side of injury and noninjury regions were analysed to obtain absolute concentrations and ratio relative to creatine of the neurometabolites. One-way analysis of variance was performed to compare neurometabolite concentrations of the three groups, and a correlation study was done between the neurometabolite concentration and Glasgow Coma Scale.
RESULTS: Significant difference was found in ratio of N-acetylaspartate to creatine (NAA/Cr + PCr) (χ2(2) = 0.22, P

Matched MeSH terms: Aspartic Acid/analogs & derivatives*; Aspartic Acid/metabolism
Fulltext Amino acid sequence and structural comparison of BACE1 and BACE2 using evolutionary trace method

Mirsafian H, Mat Ripen A, Merican AF, Bin Mohamad S

ScientificWorldJournal, 2014;2014:482463.
PMID: 25254246 DOI: 10.1155/2014/482463

Beta-amyloid precursor protein cleavage enzyme 1 (BACE1) and beta-amyloid precursor protein cleavage enzyme 2 (BACE2), members of aspartyl protease family, are close homologues and have high similarity in their protein crystal structures. However, their enzymatic properties differ leading to disparate clinical consequences. In order to identify the residues that are responsible for such differences, we used evolutionary trace (ET) method to compare the amino acid conservation patterns of BACE1 and BACE2 in several mammalian species. We found that, in BACE1 and BACE2 structures, most of the ligand binding sites are conserved which indicate their enzymatic property of aspartyl protease family members. The other conserved residues are more or less randomly localized in other parts of the structures. Four group-specific residues were identified at the ligand binding site of BACE1 and BACE2. We postulated that these residues would be essential for selectivity of BACE1 and BACE2 biological functions and could be sites of interest for the design of selective inhibitors targeting either BACE1 or BACE2.

Matched MeSH terms: Aspartic Acid Endopeptidases/genetics*; Aspartic Acid Endopeptidases/metabolism; Aspartic Acid Endopeptidases/chemistry
Fulltext Kinetic characterization of Channa striatus muscle sarcoplasmic and myofibrillar protein hydrolysates

Ghassem M, Fern SS, Said M, Ali ZM, Ibrahim S, Babji AS

J Food Sci Technol, 2014 Mar;51(3):467-75.
PMID: 24587521 DOI: 10.1007/s13197-011-0526-6

This study was conducted to evaluate the kinetic characteristics of proteolytic activity of proteases on Channa striatus protein fractions. Degree of hydrolysis (DH), amino acid composition and kinetic parameters of sarcoplasmic and myofibrillar proteins were investigated when incubated with proteinase K and thermolysin, separately. After 30 min incubation with proteases, a decrease in DH of sarcoplasmic protein was observed whereas, hydrolysis of myofibrillar protein with proteases took 2 h with an increase in DH. The major amino acids were glutamic acid (16.6%) in thermolysin- myofibrillar hydrolysate followed by aspartic acid (11.1%) in sarcoplasmic protein fraction with no enzyme treatment and lysine (10%) in thermolysin-myofibrillar hydrolysate. The apparent Michaelis constant of proteinase K was lower than thermolysin for both sarcoplasmic and myofibrillar proteins. However, rate of turnover and enzyme efficiency suggested that sarcoplasmic and myofibrillar proteins are suitable substrates for proteinase K and thermolysin hydrolytic reaction, respectively.

Matched MeSH terms: Aspartic Acid
In silico mutation on a mutant lipase from Acinetobacter haemolyticus towards enhancing alkaline stability

Anuar NFSK, Wahab RA, Huyop F, Halim KBA, Hamid AAA

J Biomol Struct Dyn, 2020 Sep;38(15):4493-4507.
PMID: 31630644 DOI: 10.1080/07391102.2019.1683074

Alkaline-stable lipases are highly valuable biocatalysts that catalyze reactions under highly basic conditions. Herein, computational predictions of lipase from Acinetobacter haemolyticus and its mutant, Mut-LipKV1 was performed to identify functionally relevant mutations that enhance pH performance under increasing basicity. Mut-LipKV1 was constructed by in silico site directed mutagenesis of several outer loop acidic residues, aspartic acid (Asp) into basic ones, lysine (Lys) at positions 51, 122 and 247, followed by simulation under extreme pH conditions (pH 8.0-pH 12.0). The energy minimized Mut-LipKV1 model exhibited good quality as shown by PROCHECK, ERRAT and Verify3D data that corresponded to 79.2, 88.82 and 89.42% in comparison to 75.2, 86.15, and 95.19% in the wild-type. Electrostatic surface potentials and charge distributions of the Mut-LipKV1 model was more stable and better adapted to conditions of elevated pHs (pH 8.0 - 10.0). Mut-LipKV1 exhibited a mixture of neutral and positive surface charge distribution compared to the predominantly negative charge in the wild-type lipase at pH 8.0. Data of molecular dynamics simulations also supported the increased alkaline-stability of Mut-LipKV1, wherein the lipase was more stable at a higher pH 9.0 (RMSD = ∼0.3 nm, RMSF = ∼0.05-0.2 nm), over the optimal pH 8.0 of the wild-type lipase (RMSD = 0.3 nm, RMSF = 0.05-0.20 nm). Thus, the adaptive strategy of replacing surface aspartic acid to lysine in lipase was successful in yielding a more alkaline-stable Mut-LipKV1 under elevated basic conditions.Communicated by Ramaswamy H. Sarma.

Matched MeSH terms: Aspartic Acid
Purification and comparison of intracellular proteinase A in Candida spp. isolates from Malaysian and Iranian patients and infected mice

Amri Saroukolaei S, Pei Pei C, Shokri H, Asadi F

J Mycol Med, 2012 Jun;22(2):149-59.
PMID: 23518017 DOI: 10.1016/j.mycmed.2012.01.002

To compare the specific intracellular proteinase A activity in clinical isolates of Candida species isolated from Iranian and Malaysian patients, the blood and kidneys of mice infected by Candida cells isolated from these human patients.

Matched MeSH terms: Aspartic Acid Endopeptidases/isolation & purification*; Aspartic Acid Endopeptidases/metabolism
Fulltext Inhibition of hyphae formation and SIR2 expression in Candida albicans treated with fresh Allium sativum (garlic) extract

Low CF, Chong PP, Yong PV, Lim CS, Ahmad Z, Othman F

J Appl Microbiol, 2008 Dec;105(6):2169-77.
PMID: 19120662 DOI: 10.1111/j.1365-2672.2008.03912.x

The aims of the present study were to determine whether Allium sativum (garlic) extract has any effect on the morphology transformation of Candida albicans, and to investigate whether it could alter the gene expression level of SIR2, a morphogenetic control gene and SAP4, a gene encoding secreted aspartyl proteinase.

Matched MeSH terms: Aspartic Acid Endopeptidases/genetics; Aspartic Acid Endopeptidases/metabolism
In vivo proton magnetic resonance spectroscopy (1H-MRS) evaluation of the metabolite concentration of optic radiation in primary open angle glaucoma

Sidek S, Ramli N, Rahmat K, Ramli NM, Abdulrahman F, Kuo TL

Eur Radiol, 2016 Dec;26(12):4404-4412.
PMID: 26943134

OBJECTIVE: To compare the metabolite concentration of optic radiation in glaucoma patients with that of healthy subjects using Proton Magnetic Resonance Spectroscopy (1H-MRS).
METHODS: 1H-MRS utilising the Single-Voxel Spectroscopy (SVS) technique was performed using a 3.0Tesla MRI on 45 optic radiations (15 from healthy subjects, 15 from mild glaucoma patients, and 15 from severe glaucoma patients). A standardised Volume of Interest (VOI) of 20 × 20 × 20 mm was placed in the region of optic radiation. Mild and severe glaucoma patients were categorised based on the Hodapp-Parrish-Anderson (HPA) classification. Mean and multiple group comparisons for metabolite concentration and metabolite concentration ratio between glaucoma grades and healthy subjects were obtained using one-way ANOVA.
RESULTS: The metabolite concentration and metabolite concentration ratio between the optic radiations of glaucoma patients and healthy subjects did not demonstrate any significant difference (p > 0.05).
CONCLUSION: Our findings show no significant alteration of metabolite concentration associated with neurodegeneration that could be measured by single-voxel 1H-MRS in optic radiation among glaucoma patients.
KEY POINTS: • Glaucoma disease has a neurodegenerative component. • Metabolite changes have been observed in the neurodegenerative process in the brain. • Using SVS, no metabolite changes in optic radiation were attributed to glaucoma.

Matched MeSH terms: Aspartic Acid/analogs & derivatives; Aspartic Acid/metabolism
A Comprehensive Review on L-Asparaginase and Its Applications

Batool T, Makky EA, Jalal M, Yusoff MM

Appl Biochem Biotechnol, 2016 Mar;178(5):900-23.
PMID: 26547852 DOI: 10.1007/s12010-015-1917-3

L-asparaginase (LA) catalyzes the degradation of asparagine, an essential amino acid for leukemic cells, into ammonia and aspartate. Owing to its ability to inhibit protein biosynthesis in lymphoblasts, LA is used to treat acute lymphoblastic leukemia (ALL). Different isozymes of this enzyme have been isolated from a wide range of organisms, including plants and terrestrial and marine microorganisms. Pieces of information about the three-dimensional structure of L-asparaginase from Escherichia coli and Erwinia sp. have identified residues that are essential for catalytic activity. This review catalogues the major sources of L-asparaginase, the methods of its production through the solid state (SSF) and submerged (SmF) fermentation, purification, and characterization as well as its biological roles. In the same breath, this article explores both the past and present applications of this important enzyme and discusses its future prospects.

Matched MeSH terms: Aspartic Acid
Fulltext Periscope: quantitative prediction of soluble protein expression in the periplasm of Escherichia coli

Chang CC, Li C, Webb GI, Tey B, Song J, Ramanan RN

Sci Rep, 2016;6:21844.
PMID: 26931649 DOI: 10.1038/srep21844

Periplasmic expression of soluble proteins in Escherichia coli not only offers a much-simplified downstream purification process, but also enhances the probability of obtaining correctly folded and biologically active proteins. Different combinations of signal peptides and target proteins lead to different soluble protein expression levels, ranging from negligible to several grams per litre. Accurate algorithms for rational selection of promising candidates can serve as a powerful tool to complement with current trial-and-error approaches. Accordingly, proteomics studies can be conducted with greater efficiency and cost-effectiveness. Here, we developed a predictor with a two-stage architecture, to predict the real-valued expression level of target protein in the periplasm. The output of the first-stage support vector machine (SVM) classifier determines which second-stage support vector regression (SVR) classifier to be used. When tested on an independent test dataset, the predictor achieved an overall prediction accuracy of 78% and a Pearson's correlation coefficient (PCC) of 0.77. We further illustrate the relative importance of various features with respect to different models. The results indicate that the occurrence of dipeptide glutamine and aspartic acid is the most important feature for the classification model. Finally, we provide access to the implemented predictor through the Periscope webserver, freely accessible at http://lightning.med.monash.edu/periscope/.

Matched MeSH terms: Aspartic Acid
Fulltext Effects of Inclusion of Different Doses of Persicaria odorata Leaf Meal (POLM) in Broiler Chicken Feed on Biochemical and Haematological Blood Indicators and Liver Histomorphological Changes

Abdul Basit M, Abdul Kadir A, Loh TC, Abdul Aziz S, Salleh A, Kaka U, et al.

Animals (Basel), 2020 Jul 16;10(7).
PMID: 32708616 DOI: 10.3390/ani10071209

This research was conducted to estimate the effects of Persicaria odorata leaf meal (POLM) on haematological indices, serum biochemical attributes, and internal organs parameters, including histomorphological features of the liver, in broiler chickens. A total of 120 one-day-old male broiler chicks (Cobb-500) were randomly allocated into four experimental groups. The dietary treatments were basal diet (BD), which served as the control (C), along with BD + 2 g/kg POLM (Po2), BD + 4 g/kg POLM (Po4), BD + 8 g/kg POLM (Po8), which were the supplemented groups. The body weight gain (BWG) showed a linear increase and feed conversion ratio (FCR) showed a linear decrease with increasing POLM dosage at day 42 (p ˂ 0.05) and for the overall growth performance period (p ˂ 0.01). On day 21 and day 42, the values of red blood cells (RBCs), white blood cells (WBCs), haemoglobin (Hb), and packed cell volume (PCV) showed linear increases (p ˂0.05) as the dosage of POLM increased in the diet. On day 21, dietary supplementation of POLM linearly decreased (p ˂ 0.05) the serum activity of alkaline phosphatase (ALP), aspartate aminotransaminase (AST), alanine aminotransaminase (ALT), and serum levels of urea and creatinine. On the other hand, serum levels of total protein (TP), albumin, and globulin showed a linear increase (p ˂ 0.05) as the POLM dosage increased. On day 42, the serum activity of AST and ALT and serum levels of glucose, cholesterol, triglycerides, urea, and creatinine showed linear decreases (p ˂ 0.05) with increased levels of POLM in the diet. However, POLM supplementation linearly increased (p ˂ 0.05) the serum levels of TP and globulin. Dietary inclusion of POLM did not influence the organ parameters and showed no adverse effects on the liver histomorphology. In conclusion, supplementation of POLM increased the growth performance, improving haematological indices and serum biochemistry profiles of broiler chickens without any deleterious effects on the liver histomorphology. The results of the present study provide evidence that POLM can be safely used at a dose rate of 8 g/kg of feed as an alternative to conventional antimicrobial growth promoters (AGPs).

Matched MeSH terms: Aspartic Acid
Construction of A Preliminary Three-Dimensional Structure Simian betaretrovirus Serotype-2 (SRV-2) Reverse Transcriptase Isolated from Indonesian Cynomolgus Monkey

Saepuloh U, Iskandriati D, Pamungkas J, Solihin DD, Mariya SS, Sajuthi D

Trop Life Sci Res, 2020 Oct;31(3):47-61.
PMID: 33214855 DOI: 10.21315/tlsr2020.31.3.4

Simian betaretrovirus serotype-2 (SRV-2) is an important pathogenic agent in Asian macaques. It is a potential confounding variable in biomedical research. SRV-2 also provides a valuable viral model compared to other retroviruses which can be used for understanding many aspects of retroviral-host interactions and immunosuppression, infection mechanism, retroviral structure, antiretroviral and vaccine development. In this study, we isolated the gene encoding reverse transcriptase enzyme (RT) of SRV-2 that infected Indonesian cynomolgus monkey (Mf ET1006) and predicted the three dimensional structure model using the iterative threading assembly refinement (I-TASSER) computational programme. This SRV-2 RT Mf ET1006 consisted of 547 amino acids at nucleotide position 3284-4925 of whole genome SRV-2. The polymerase active site located in the finger/palm subdomain characterised by three conserved catalytic aspartates (Asp90, Asp165, Asp166), and has a highly conserved YMDD motif as Tyr163, Met164, Asp165 and Asp166. We estimated that this SRV-2 RT Mf ET1006 structure has the accuracy of template modelling score (TM-score 0.90 ± 0.06) and root mean square deviation (RMSD) 4.7 ± 3.1Å, indicating that this model can be trusted and the accuracy can be seen from the appearance of protein folding in tertiary structure. The superpositionings between SRV-2 RT Mf ET1006 and Human Immunodeficiency Virus-1 (HIV-1) RT were performed to predict the structural in details and to optimise the best fits for illustrations. This SRV-2 RT Mf ET1006 structure model has the highest homology to HIV-1 RT (2B6A.pdb) with estimated accuracy at TM-score 0.911, RMSD 1.85 Å, and coverage of 0.953. This preliminary study of SRV-2 RT Mf ET1006 structure modelling is intriguing and provide some information to explore the molecular characteristic and biochemical mechanism of this enzyme.

Matched MeSH terms: Aspartic Acid
Enhanced production of short-peptide tagged Ss3a recombinant protein as a novel potential biomarker for strongyloidiasis

Mohd-Hassan NH, Noordin R, Arifin N

Trop Biomed, 2020 Sep 01;37(3):578-586.
PMID: 33612773 DOI: 10.47665/tb.37.3.578

Strongyloidiasis is a mysterious yet important parasitic disease that is hard to diagnose. While microscopic examination remains a "controversial" gold standard method, improved diagnosis is achieved through confirmatory assays with serological and/or molecular diagnostic approaches. In the current serodiagnosis of strongyloidiasis, recombinant proteins have been adopted in place of the use of native parasite antigens, although the availability of diagnostically potential proteins are still limited. Here, we introduce a novel Strongyloides recombinant protein that is uniquely attached to two different short peptide tags as a potential diagnostic biomarker for serodiagnosis of strongyloidiasis, namely lysine (7K) and aspartic acid (7D). The work presented focus on improving the yield and purity of the previously unexpressed recombinant protein. Preliminary diagnostic evaluation of the recombinant favors Ss3a7K protein owing to its higher antigenicity performance with 80% sensitivity and 100% specificity, respectively.

Matched MeSH terms: Aspartic Acid
Fulltext Evaluation of umaminess in green mussel hydrolysate (Perna viridis) produced in the presence of sodium tripolyphosphate and NaCl

Normah, I., Nurdalila Diyana, M.R.

International Food Research Journal, 2018;25(6):524-530.
MyJurnal

This study was conducted to evaluate umami taste in protein hydrolysate produced from green mussel (Perna viridis) by hydrolysing with flavorzyme at pH 8, enzyme substrate ratio (E/S) 3% with or without the presence of 0.4% sodium tripolyphosphate (STPP) and 1.5% NaCI. Degree of hydrolysis (DH), yield, amino acid compositions, molecular weight distribution and sensory evaluation were determined. The highest DH (23.18%), darkest color and highest yield (8.34%) were recorded for hydrolysate produced in the presence of both STPP and NaCI. Electrophoresis analysis showed the presence of protein bands between 10 to 70 kDa where hydrolysate with addition of STPP and NaCI had bands with lower intensities. Amino acids which contribute to the umami taste such as glutamic acid, glycine and aspartic acid were higher in hydrolysate produced with STPP and NaCI addition. The hydrolysate has lesser fishy odor and flavor than those produced with only in the presence of flavorzyme and was also rated with highest score for all the five basic tastes including bitterness. However, the score for bitterness was still lower than the reference solutions. Therefore, green mussel hydrolysate produced in this study has a good potential as a food flavorant.

Matched MeSH terms: Aspartic Acid
Fulltext Extrusion enhances apparent metabolizable energy, ileal protein and amino acid digestibility of palm kernel cake in broilers

Faridah HS, Goh YM, Noordin MM, Liang JB

Asian-Australas J Anim Sci, 2020 Dec;33(12):1965-1974.
PMID: 32164059 DOI: 10.5713/ajas.19.0964

OBJECTIVE: This study consisted of two stages; the first was to determine the effect of extrusion and sieving treatments on the chemical properties of palm kernel cake (PKC), and accordingly, a follow-up experiment (second stage) was conducted to determine and compare the apparent metabolizable energy (AME), and protein and amino acid digestibility of extruded and sieved PKC.
METHODS: Two physical treatments, namely extrusion (using temperature profiles of 90°C/100°C/100°C, 90°C/100°C/110°C, and 90°C/100°C/120°C) and sieving (to 8 particles sizes ranging from >8.00 to 0.15 mm) were carried out to determine their effects on chemical properties, primarily crude protein (CP) and fiber contents of PKC. Based on the results from the above study, PKC that extruded with temperature profile 90/100/110°C and of sieved size between 1.5 to 0.15 mm (which made up of near 60% of total samples) were used to determine treatments effect on AME and CP and amino acid digestibility. The second stage experiment was conducted using 64 male Cobb 500 chickens randomly assigned to 16 cages (4 cages [or replicates] per treatment) to the following four dietary groups: i) basal (control) diet, ii) basal diet containing 20% untreated PKC, iii) basal diet containing 20% extruded PKC (EPKC), and iv) basal diet containing 20% sieved PKC (SPKC).
RESULTS: Extrusion and sieving had no effect on CP and ash contents of PKC, however, both treatments reduced (p<0.05) crude fiber by 21% and 19%, respectively. Overall, extrusion and sieving reduced content of most of the amino acids except for aspartate, glutamate, alanine and lysine which increased, while serine, cysteine and tryptophan remained unchanged. Extrusion resulted in 6% increase (p<0.05) in AME and enhanced CP digestibility (p<0.05) by 32%, as compared to the untreated PKC while sieving had no effect on AME but improved CP digestibility by 39% which was not significantly different from that by extrusion.
CONCLUSION: Extrusion is more effective than sieving and serves as a practical method to enhance AME and digestibility of CP and several amino acids in broiler chickens.

Matched MeSH terms: Aspartic Acid
Fulltext Endophytic l-asparaginase-producing fungi from plants associated with anticancer properties

Chow Y, Ting AS

J Adv Res, 2015 Nov;6(6):869-76.
PMID: 26644924 DOI: 10.1016/j.jare.2014.07.005

Endophytes are novel sources of natural bioactive compounds. This study seeks endophytes that produce the anticancer enzyme l-asparaginase, to harness their potential for mass production. Four plants with anticancer properties; Cymbopogon citratus, Murraya koenigii, Oldenlandia diffusa and Pereskia bleo, were selected as host plants. l-Asparaginase-producing endophytes were detected by the formation of pink zones on agar, a result of hydrolyzes of asparagine into aspartic acid and ammonia that converts the phenol red dye indicator from yellow (acidic condition) to pink (alkaline condition). The anticancer enzyme asparaginase was further quantified via Nesslerization. Results revealed that a total of 89 morphotypes were isolated; mostly from P. bleo (40), followed by O. diffusa (25), C. citratus (14) and M. koenigii (10). Only 25 of these morphotypes produced l-asparaginase, mostly from P. bleo and their asparaginase activities were between 0.0069 and 0.025 μM mL(-1) min(-1). l-Asparaginase producing isolates were identified as probable species of the genus Colletotrichum, Fusarium, Phoma and Penicillium. Studies here revealed that endophytes are good alternative sources for l-asparaginase production and they can be sourced from anticancer plants, particularly P. bleo.

Matched MeSH terms: Aspartic Acid
Fulltext Exploring Changes in Thalamus Metabolites as Diagnostic Biomarkers in Idiopathic Generalised Epilepsy Patients Using Magnetic Resonance Spectroscopy

Abedi-Firouzjah R, Rostamzadeh A, Banaei A, Shafiee M, Moghaddam ZM, Vafapour H

Malays J Med Sci, 2020 Feb;27(1):78-86.
PMID: 32158347 DOI: 10.21315/mjms2020.27.1.8

Introduction: Idiopathic generalised epilepsy (IGE) refers to a group of epilepsies resulting from the activation of neurons in the whole brain. This study aimed to evaluate the metabolite changes in thalamus as diagnostic biomarkers in IGE patients compared to healthy individuals using magnetic resonance spectroscopy (MRS) technique.
Methods: The MRS was performed on 35 IGE patients (26 women and 11 men) with average age of 32 (ranged from 18 to 43) and 35 healthy individuals (13 women and 22 men) with average age of 31 (ranged from 21 to 50) as the control group. The levels of N-acetylaspartate (NAA), creatine (Cr) and choline (Cho) were measured using MRS. The NAA/Cr and NAA/Cho ratios were calculated for all participants. These values were statistically compared using t-test between the groups.
Results: The NAA had significant lower values in IGE patients, 9.6 (SD = 0.8) and 9.9 (SD = 0.7) for right and left thalamus, respectively, compared to 10.9 (SD = 0.9) and 10.7 (SD = 0.9) in control group. The Cr values in the left side of thalamus were significantly higher in IGE patients (6.7 [SD = 0.8] versus 5.8 [SD = 0.5]); however, there was no difference in right thalamus. Measurements showed no difference for amounts of Cho between the groups in both sides of thalamus. The NAA/Cr ratio was 1.48 (SD = 0.14) and 1.48 (SD = 0.16) for right and left thalamus, respectively, in IGE patients in comparison with 1.83 (SD = 0.2) and 1.86 (SD = 0.26) in controls. There was no meaningful variation between the NAA/Cho ratio of the right and left thalamus among the groups.
Conclusion: Thalamic NAA, Cr and NAA/Cr ratio values in IGE patients showed statistical differences compared to healthy individuals. Evaluating metabolites variations in thalamus using MRS is suggested for differentiating IGE patients from healthy individuals.

Matched MeSH terms: Aspartic Acid

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