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Fulltext IMAAAGINE: a webserver for searching hypothetical 3D amino acid side chain arrangements in the Protein Data Bank

Nadzirin N, Willett P, Artymiuk PJ, Firdaus-Raih M

Nucleic Acids Res, 2013 Jul;41(Web Server issue):W432-40.
PMID: 23716645 DOI: 10.1093/nar/gkt431

We describe a server that allows the interrogation of the Protein Data Bank for hypothetical 3D side chain patterns that are not limited to known patterns from existing 3D structures. A minimal side chain description allows a variety of side chain orientations to exist within the pattern, and generic side chain types such as acid, base and hydroxyl-containing can be additionally deployed in the search query. Moreover, only a subset of distances between the side chains need be specified. We illustrate these capabilities in case studies involving arginine stacks, serine-acid group arrangements and multiple catalytic triad-like configurations. The IMAAAGINE server can be accessed at http://mfrlab.org/grafss/imaaagine/.

Matched MeSH terms: Amino Acids/chemistry*
Soy sauce and its umami taste: a link from the past to current situation

Lioe HN, Selamat J, Yasuda M

J Food Sci, 2010 Apr;75(3):R71-6.
PMID: 20492309 DOI: 10.1111/j.1750-3841.2010.01529.x

Soy sauce taste has become a focus of umami taste research. Umami taste is a 5th basic taste, which is associated to a palatable and pleasurable taste of food. Soy sauce has been used as an umami seasoning since the ancient time in Asia. The complex fermentation process occurred to soy beans, as the raw material in the soy sauce production, gives a distinct delicious taste. The recent investigation on Japanese and Indonesian soy sauces revealed that this taste is primarily due to umami components which have molecular weights lower than 500 Da. Free amino acids are the low molecular compounds that have an important role to the taste, in the presence of sodium salt. The intense umami taste found in the soy sauces may also be a result from the interaction between umami components and other tastants. Small peptides are also present, but have very low, almost undetected umami taste intensities investigated in their fractions.

Matched MeSH terms: Amino Acids/analysis
Ileal endogenous amino acid flow of broiler chickens under high ambient temperature

Soleimani AF, Kasim A, Alimon AR, Meimandipour A, Zulkifli I

J Anim Physiol Anim Nutr (Berl), 2010 Oct;94(5):641-7.
PMID: 20050954 DOI: 10.1111/j.1439-0396.2009.00951.x

High environmental temperature has detrimental effects on the gastrointestinal tract of poultry. An experiment was conducted to determine the effect of acute heat stress on endogenous amino acid (EAA) flow in broiler chickens. A total of 90, day-old broiler chicks were housed in battery cages in an environmentally controlled chamber. Chicks were fed a nitrogen-free diet on day 42 following either no heat exposure (no-heat) or 2 weeks exposure to 35 ± 1 °C for 3 h from days 28 to 42 (2-week heat) or 1 week exposure to 35 ± 1 °C for 3 h from days 35 to 42 (1 week heat). The most abundant amino acid in the ileal flow was glutamic acid, followed by aspartic acid, serine and threonine in non-heat stressed group. The EAA flow in 1-week heat and 2-week heat birds were significantly (p < 0.05) higher than those under no heat exposure (14682, 11161 and 9597 mg/kg of dry matter intake respectively). Moreover, the EAA flow of 2-week heat group was less than 1-week heat group by approximately 36%. These observations suggest that the effect of heat stress on EAA flow is mostly quantitative; however, heat stress may also alter the content of EAA flow qualitatively.

Matched MeSH terms: Amino Acids/metabolism*
Effects of preparation methods on protein and amino acid contents of various eggs available in Malaysian local markets

Ismail M, Mariod A, Pin SS

Acta Sci Pol Technol Aliment, 2013 Jan-Mar;12(1):21-31.
PMID: 24584862

BACKGROUND:
The effect of preparation methods (raw, half-boiled and hard-boiled) on protein and amino acid contents, as well as the protein quality (amino acid score) of regular, kampung and nutrient enriched Malaysian eggs was investigated.
METHODS:
The protein content was determined using a semi-micro Kjeldahl method whereas the amino acid composition was determined using HPLC.
RESULTS:
The protein content of raw regular, kampung and nutrient enriched eggs were 49.9 ±0.2%, 55.8 ±0.2% and 56.5 ±0.5%, respectively. The protein content of hard-boiled eggs of regular, kampung and nutrient enriched eggs was 56.8 ±0.1%, 54.7 ±0.1%, and 53.7 ±0.5%, while that for half-boiled eggs of regular, kampung and nutrient enriched eggs was 54.7 ±0.6%, 53.4 ±0.4%, and 55.1 ±0.7%, respectively. There were significant differences (p < 0.05) in protein and amino acid contents of half-boiled, hard-boiled as compared with raw samples, and valine was found as the limiting amino acid. It was found that there were significant differences (p < 0.05) of total amino score in regular, kampung and nutrient enriched eggs after heat treatments.Furthermore, hard-boiling (100°C) for 10 minutes and half-boiling (100°C) for 5 minutes affects the total amino score, which in turn alter the protein quality of the egg.

Matched MeSH terms: Amino Acids/analysis*
Effects of aminoacids on the autooxidation of 3,5-di-tert-butylcatechol in the presence of surface-active copper(II) complexes

Lim YY, Liew LP

J Colloid Interface Sci, 2002 Nov 15;255(2):425-7.
PMID: 12505092

The rate of autooxidation of 3,5-di-tert-butylcatechol (3,5-DTBC) in the presence of micelles formed from mixing equal concentrations of [Cu(C(12)-tmed)Br(2)] (where C(12)-tmed is N,N,N'-trimethyl-N'-dodecylethylenediamine) and several amino acids has been investigated. It was found that the rate in air-saturated solution is very much dependent on pH, which affects the availability of copper(II) coordination site for the catechol and the degree of micellization. At a given pH, the rates in [Cu(C(12)-tmed)Br(2)] micellar media are greatly enhanced in the presence sodium halide.

Matched MeSH terms: Amino Acids/chemistry*
Application of the artificial neural network in quantitative structure-gradient elution retention relationship of phenylthiocarbamyl amino acids derivatives

Tham SY, Agatonovic-Kustrin S

J Pharm Biomed Anal, 2002 May 15;28(3-4):581-90.
PMID: 12008137

Quantitative structure-retention relationship(QSRR) method was used to model reversed-phase high-performance liquid chromatography (RP-HPLC) separation of 18 selected amino acids. Retention data for phenylthiocarbamyl (PTC) amino acids derivatives were obtained using gradient elution on ODS column with mobile phase of varying acetonitrile, acetate buffer and containing 0.5 ml/l of triethylamine (TEA). Molecular structure of each amino acid was encoded with 36 calculated molecular descriptors. The correlation between the molecular descriptors and the retention time of the compounds in the calibration set was established using the genetic neural network method. A genetic algorithm (GA) was used to select important molecular descriptors and supervised artificial neural network (ANN) was used to correlate mobile phase composition and selected descriptors with the experimentally derived retention times. Retention time values were used as the network's output and calculated molecular descriptors and mobile phase composition as the inputs. The best model with five input descriptors was chosen, and the significance of the selected descriptors for amino acid separation was examined. Results confirmed the dominant role of the organic modifier in such chromatographic systems in addition to lipophilicity (log P) and molecular size and shape (topological indices) of investigated solutes.

Matched MeSH terms: Amino Acids/analysis*
Fulltext Evolutionary and genomic analysis of four SARS-CoV-2 isolates circulating in March 2020 in Sri Lanka; Additional evidence on multiple introduction and further transmission

Satharasinghe DA, Parakatawella PMSDK, Premarathne JMKJK, Jayasooriya LJPAP, Prathapasinghe GA, Yeap SK

Epidemiol Infect, 2021 03 16;149:e78.
PMID: 33722321 DOI: 10.1017/S0950268821000583

The molecular epidemiology of the virus and mapping helps understand the epidemics' evolution and apply quick control measures. This study provides genomic evidence of multiple severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) introductions into Sri Lanka and virus evolution during circulation. Whole-genome sequences of four SARS-CoV-2 strains obtained from coronavirus disease 2019 (COVID-19) positive patients reported in Sri Lanka during March 2020 were compared with sequences from Europe, Asia, Africa, Australia and North America. The phylogenetic analysis revealed that the sequence of the sample of the first local patient collected on 10 March, who contacted tourists from Italy, was clustered with SARS-CoV-2 strains collected from Italy, Germany, France and Mexico. Subsequently, the sequence of the isolate obtained on 19 March also clustered in the same group with the samples collected in March and April from Belgium, France, India and South Africa. The other two strains of SARS-CoV-2 were segregated from the main cluster, and the sample collected from 16 March clustered with England and the sample collected on 30 March showed the highest genetic divergence to the isolate of Wuhan, China. Here we report the first molecular epidemiological study conducted on circulating SARS-CoV-2 in Sri Lanka. The finding provides the robustness of molecular epidemiological tools and their application in tracing possible exposure in disease transmission during the pandemic.

Matched MeSH terms: Amino Acids/analysis
Role of surface-exposed charged basic amino acids (Lys, Arg) and guanidination in insulin on the interaction and stability of insulin-insulin receptor complex

Lee VS, Sukumaran SD, Tan PK, Kuppusamy UR, Arumugam B

Comput Biol Chem, 2021 Jun;92:107501.
PMID: 33989998 DOI: 10.1016/j.compbiolchem.2021.107501

Naturally occurring proteins are emerging as novel therapeutics in the protein-based biopharmaceutical industry for the treatment of diabetes and obesity. However, proteins are not suitable for oral delivery due to short half-life, reduced physical and chemical stability and low permeability across the membrane. Chemical modification has been identified as a formulation strategy to enhance the stability and bioavailability of protein drugs. The present study aims to study the effect of charge-specific modification of basic amino acids (Lys, Arg) and guanidination on the interaction of insulin with its receptor using molecular modelling. Our investigation revealed that the guanidination of insulin (Lys-NHC = NHNH2) enhanced and exerted stronger binding of the protein to its receptor through electrostatic interaction than native insulin (Lys-NH3+). Point mutations of Lys and Arg (R22, K29; R22K, K29; R22, K29R; R22K, K29R) were attempted and the effects on the interaction and stability between insulin/modified insulins and insulin receptor were also analyzed in this study. The findings from the study are expected to provide a better understanding of the possible mechanism of action of the modified protein at a molecular level before advancing to real experiments.

Matched MeSH terms: Amino Acids, Basic/chemistry*
Fulltext Proximate Analysis of Selected Macroalgal Species from the Persian Gulf as a Nutritional Resource

Pirian K, Jeliani ZZ, Arman M, Sohrabipour J, Yousefzadi M

Trop Life Sci Res, 2020 Apr;31(1):1-17.
PMID: 32963708 DOI: 10.21315/tlsr2020.31.1.1

Nowadays the exploration and utilisation of food and feed from marine origin is becoming more important with the increase of human population. Macroalgae are rich in nutritious compounds, which can directly be used in human and animal feed industries. The current study presents the screening of chemical components of eight macroalgae species, Sargassum boveanum, Sirophysalis trinodis, Hypnea caroides, Palisda perforata, Galaxaura rugosa, Caulerpa racemose, Caulerpa sertularioides and Bryopsis corticolans from the Persian Gulf. The results revealed that the eight studied algal species possess high protein (14.46% to 38.20%), lipid (1.27% to 9.13%) and ash (15.50% to 49.14%) contents. The fatty acids and amino acids profile showed the presence of essential fatty acids and amino acids with high nutritional value. Phaeophyta species, S. boveanum and S. trinodis, showed the highest value of ash content and polyunsaturated fatty acids while Chlorophyta species, C. racemose, C. sertularioides and B. corticolans, showed the highest level of lipid and protein contents. Rhodophyta species, G. rugosa and P. perforata, showed the highest essential amino acid content. In conclusion, this study demonstrates the potential of the studied marine species as a nutritional source for human and animal uses.

Matched MeSH terms: Amino Acids; Amino Acids, Essential
Fulltext Preliminary studies on the evaluation of nutritional composition of unripe and ripe ‘Kundang’ fruits (Bouea macrophylla Griffith)

Rajan, Nithiya Shanmuga, Bhat,Rajeev, Karim, A.A.

International Food Research Journal, 2014;21(3):985-990.
MyJurnal

Unripe and ripe kundang fruits (Bouea macrophylla Griffith) is either consumed fresh or is cooked in Malaysia. In this study composition of unripe and ripe fruits (proximate, amino acids profile, minerals and heavy metal contents) were evaluated. Results obtained showed unripe kundang fruit to possess higher moisture, ash, crude lipid, crude fiber and crude protein contents than the ripe fruits. With regard to amino acid contents, unripe fruits had higher content of essential amino acids. The unripe and ripe fruits were found to be rich in essential minerals with potassium (K) to be in abundance. Heavy metals such as cadmium, nickel, mercury, lead and arsenic, were detected in trace amounts (< 5.0 mg/kg) in both unripe and ripe fruits. Through this investigation, it is concluded that both unripe and ripe fruits to posses’ adequate amount of nutritionally important compounds beneficial to human health and can be explored for commercial purposes.

Matched MeSH terms: Amino Acids; Amino Acids, Essential
Comparison of physicochemical and functional properties of duck feet and bovine gelatins

Kuan YH, Nafchi AM, Huda N, Ariffin F, Karim AA

J Sci Food Agric, 2017 Mar;97(5):1663-1671.
PMID: 27465360 DOI: 10.1002/jsfa.7970

BACKGROUND: Previous studies have indicated that duck feet are a rich source of gelatin extractable from avian sources. In this study, the physicochemical and functional properties of avian gelatin extracted from duck feet (DFG) with acetic acid were compared with those of commercial bovine gelatin (BG).
RESULTS: The yield of DFG obtained in this study was 7.01 ± 0.31%. High-performance liquid chromatography analysis indicated that the imino acid content was slightly lower for DFG compared with BG (P < 0.05). Differences in molecular size and amino acids between DFG and BG were also observed. The isoelectric points of DFG and BG were at pH 8 and 5 respectively, and the overall protein solubility of BG was higher than that of DFG. Gels prepared from BG exhibited higher bloom strength, viscosity and clarity and were darker in colour compared with DFG gels (P < 0.05). The gelling and melting points of BG were 21.8 and 29.47 °C respectively, while those of DFG were 20.5 and 27.8 °C respectively. BG exhibited slightly better emulsifying and foaming properties compared with DFG.
CONCLUSION: Although some differences between DFG and BG were observed, the disparities were small, which indicates that DFG could be exploited commercially as an alternative source of gelatin. © 2016 Society of Chemical Industry.

Matched MeSH terms: Amino Acids/analysis
Fulltext Nutritional composition and amino acid profile of a sub-tropical red seaweed Gelidium pusillum collected from St. Martin’s Island, Bangladesh

Siddique, M.A.M., Khan, M.S.K., Bhuiyan, M.K.A.

International Food Research Journal, 2013;20(5):2287-2292.
MyJurnal

Nutritional fact study has prime importance to make the species edible and commercially viable to the food consumers. The proximate chemical composition and amino acid profile of Gelidium pusillum were studied to understand the nutritional status. The red seaweed Gelidium pusillum was rich in dietary fibre (24.74 ± 1.05%), lipid (2.16 ± 0.61%) and ash content (21.15 ± 0.74%). The mean protein content (11.31 ± 1.02% DW) was within the range of 10-47% for green and red seaweeds and this range was higher than Gracilaria cornea (5.47% DW), Gracilaria changgi (6.90% DW) and Eucheuma cottonii (9.76% DW). Gelidium pusillum was found to contained all the essential amino acids, which accounted for 52.08% of the total amino acids. Tyrosine (26.2 mg g-1 protein), methionine (15.8 mg g-1 protein) and Lysine (48.3 mg g-1 protein) were the limiting amino acid of Gelidium pusillum. However, the levels of other essential amino acids were above the FAO/WHO requirement pattern (EAA score ranged from 1.14 to 1.62). Aspartic and glutamic acids constituted a substantial amount of the total amino acids (24.68% of total amino acid). The result from this study suggested that Gelidium pusillum could be utilized as a healthy food item for human consumption.

Matched MeSH terms: Amino Acids; Amino Acids, Essential
Fulltext Physicochemical properties of silver catfish (Pangasius sp.) frame hydrolysate

Amiza, M.A., Ow, Y.W., Faazaz, A.L.

International Food Research Journal, 2013;20(3):1255-1262.
MyJurnal

The physicochemical properties of silver catfish frame hydrolysate powder at three different degree of hydrolysis, DH43%, DH 55% and DH 68% were studied. The hydrolysates powder were obtained by hydrolysis using Alcalase®, centrifugation and spray drying of the supernatant. The study found that preparation of these hydrolysates affected the protein, ash and fat content as well as amino acid composition. As for essential amino acids, their values were generally considered as adequate as compared to the suggested essential amino acids profile of FAO/WHO. The results showed that SFHs were rich in lysine and glutamate. Hydrolysate at DH 68% exhibited better peptide solubility and water holding capacity. As degree of hydrolysis increased, emulsifying capacity and foaming capacity of the hydrolysate decreased. It was also found that the lightness in hydrolysate powder decreased with increase in degree of hydrolysis. This study shows that silver catfish frame hydrolysate has good solubility, good foaming properties and light colour profile, thus having high potential as food ingredient.

Matched MeSH terms: Amino Acids; Amino Acids, Essential
Fulltext Biochemical properties of red tilapia (Oreochromis niloticus) protein hydrolysates

Shamloo, M., Bakar, J., Mat Hashim, D., Khatib, A.

International Food Research Journal, 2012;19(1):183-188.
MyJurnal

The amino-acid composition, 2, 2-Diphenyl-1-picryhydrazyl (DPPH) radical-scavenging activity, and peptide patterns of tilapia protein hydrolysates produced by the enzymatic hydrolysis of Alcalase (AH), Flavourzyme (FH) and Protamex (PH) for 5h using pH-stat method were studied. The ratio of essential amino acids to non-essential amino acids increased after hydrolysis in all samples; however, no significant differences among them were observed. AH had a highest (P < 0.05) DPPH radical-scavenging activity, but no significant difference in the DPPH between FH and PH was observed. SDS-PAGE patterns for all the hydrolysates showed significant (P < 0.05) reduction in the number and the intensity of the bands with increasing time of hydrolysis. Flavourzyme showed the lowest rate of hydrolytic activity towards the tilapia mince.

Matched MeSH terms: Amino Acids; Amino Acids, Essential
Effect of amino acids and frequency of reuse frying oils at different temperature on acrylamide formation in palm olein and soy bean oils via modeling system

Daniali G, Jinap S, Sanny M, Tan CP

Food Chem, 2018 Apr 15;245:1-6.
PMID: 29287315 DOI: 10.1016/j.foodchem.2017.10.070

This work investigated the underlying formation of acrylamide from amino acids in frying oils during high temperatures and at different times via modeling systems. Eighteen amino acids were used in order to determine which one was more effective on acrylamide production. Significantly the highest amount of acrylamide was produced from asparagine (5987.5µg/kg) and the lowest from phenylalanine (9.25µg/kg). A constant amount of asparagine and glutamine in palm olein and soy bean oils was heated up in modelling system at different temperatures (160, 180 and 200°C) and times (1.5, 3, 4.5, 6, 7.5min). The highest amount of acrylamide was found at 200°C for 7.5min (9317 and 8511µg/kg) and lowest at 160°C for 1.5min (156 and 254µg/kg) in both frying oils and both amino acids. Direct correlations have been found between time (R2=0.884), temperature (R2=0.951) and amount of acrylamide formation, both at p<0.05.

Matched MeSH terms: Amino Acids/chemistry*
Nuclear magnetic resonance spectroscopy and liquid chromatography-mass spectrometry metabolomics studies on non-organic soybeans versus organic soybeans (Glycine max), and their fermentation by Rhizopus oligosporus

Chong SG, Ismail IS, Ahmad Azam A, Tan SJ, Shaari K, Tan JK

J Sci Food Agric, 2023 Apr;103(6):3146-3156.
PMID: 36426592 DOI: 10.1002/jsfa.12355

BACKGROUND: Soybeans (Glycine max) are high in proteins and isoflavones, which offer many health benefits. It has been suggested that the fermentation process enhances the nutrients in the soybeans. Organic foods are perceived as better than non-organic foods in terms of health benefits, yet little is known about the difference in the phytochemical content that distinguishes the quality of organic soybeans from non-organic soybeans. This study investigated the chemical profiles of non-organic (G, T, U, UB) and organic (C, COF, A, R, B, Z) soybeans (G. max [L.] Merr.) and their metabolite changes after fermentation with Rhizopus oligosporus.
RESULTS: A clear separation was only observed between non-organic G and organic Z, which were then selected for further investigation in the fermentation of soybeans (GF and ZF). All four groups (G, Z, GF, ZF) were analyzed using nuclear magnetic resonance (NMR) spectroscopy along with liquid chromatography-tandem mass spectrometry (LC-MS/MS). In this way a total of 41 and 47 metabolites were identified respectively, with 12 in common. A clear variation (|log1.5 FC| > 2 and P amino acids and organic acids were found in ZF. An additional four metabolites clustered as C-glycosylflavonoids were discovered from MS/MS-based molecular networking.
CONCLUSION: Chemical profiles of non-organic and organic soybeans exhibited no significant difference. However, the metabolite profile of the unfermented soybeans, which were higher in sugars, shifted to higher amino acid and organic acid content after fermentation, thereby potentially enhancing their nutritional value. © 2022 Society of Chemical Industry.

Matched MeSH terms: Amino Acids/analysis
Fulltext Effect of Different Amino Acids and Heating Conditions on the Formation of 2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) and Its Kinetics Formation Using Chemical Model System

Ishak AA, Selamat J, Sulaiman R, Sukor R, Abdulmalek E, Jambari NN

Molecules, 2019 Oct 24;24(21).
PMID: 31652883 DOI: 10.3390/molecules24213828

The formation of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) was investigated using a kinetic study approach as described by first-order, Arrhenius, and Eyring equations. Chemical model systems with different amino acid precursors (proline, phenylalanine, and glycine) were examined at different times (4, 8, 12, and 16 min) and temperatures (150, 180, 210, 240, and 270 °C). PhIP was detected using high-performance liquid chromatography equipped with fluorescence detector (HPLC-FLD). The good fit in first-order suggested that PhIP formation was influenced by the types of amino acids and PhIP concentration significantly increased with time and temperature (up to 240 °C). PhIP was detected in proline and phenylalanine model systems but not in the glycine model system. The phenylalanine model system demonstrated low activation energy (Ea) of 95.36 kJ/mol that resulted in a high rate of PhIP formation (great amount of PhIP formed). Based on the ∆S‡ values both proline and phenylalanine demonstrated bimolecular rate-limiting steps for PhIP formation. Altogether these kinetic results could provide valuable information in predicting the PhIP formation pathway.

Matched MeSH terms: Amino Acids/chemistry*
Fulltext Prevalence of DDC genotypes in patients with aromatic L-amino acid decarboxylase (AADC) deficiency and in silico prediction of structural protein changes

Himmelreich N, Bertoldi M, Alfadhel M, Alghamdi MA, Anikster Y, Bao X, et al.

Mol Genet Metab, 2023 Jul;139(3):107624.
PMID: 37348148 DOI: 10.1016/j.ymgme.2023.107624

Aromatic L-amino acid decarboxylase (AADC) deficiency is a rare autosomal recessive genetic disorder affecting the biosynthesis of dopamine, a precursor of both norepinephrine and epinephrine, and serotonin. Diagnosis is based on the analysis of CSF or plasma metabolites, AADC activity in plasma and genetic testing for variants in the DDC gene. The exact prevalence of AADC deficiency, the number of patients, and the variant and genotype prevalence are not known. Here, we present the DDC variant (n = 143) and genotype (n = 151) prevalence of 348 patients with AADC deficiency, 121 of whom were previously not reported. In addition, we report 26 new DDC variants, classify them according to the ACMG/AMP/ACGS recommendations for pathogenicity and score them based on the predicted structural effect. The splice variant c.714+4A>T, with a founder effect in Taiwan and China, was the most common variant (allele frequency = 32.4%), and c.[714+4A>T];[714+4A>T] was the most common genotype (genotype frequency = 21.3%). Approximately 90% of genotypes had variants classified as pathogenic or likely pathogenic, while 7% had one VUS allele and 3% had two VUS alleles. Only one benign variant was reported. Homozygous and compound heterozygous genotypes were interpreted in terms of AADC protein and categorized as: i) devoid of full-length AADC, ii) bearing one type of AADC homodimeric variant or iii) producing an AADC protein population composed of two homodimeric and one heterodimeric variant. Based on structural features, a score was attributed for all homodimers, and a tentative prediction was advanced for the heterodimer. Almost all AADC protein variants were pathogenic or likely pathogenic.

Matched MeSH terms: Amino Acids/genetics
Fulltext Association between alleles, haplotypes, and amino acid variations in HLA class II genes and type 1 diabetes in Kuwaiti children

Dashti M, Nizam R, Jacob S, Al-Kandari H, Al Ozairi E, Thanaraj TA, et al.

Front Immunol, 2023;14:1238269.
PMID: 37638053 DOI: 10.3389/fimmu.2023.1238269

Type 1 diabetes (T1D) is a complex autoimmune disorder that is highly prevalent globally. The interactions between genetic and environmental factors may trigger T1D in susceptible individuals. HLA genes play a significant role in T1D pathogenesis, and specific haplotypes are associated with an increased risk of developing the disease. Identifying risk haplotypes can greatly improve the genetic scoring for early diagnosis of T1D in difficult to rank subgroups. This study employed next-generation sequencing to evaluate the association between HLA class II alleles, haplotypes, and amino acids and T1D, by recruiting 95 children with T1D and 150 controls in the Kuwaiti population. Significant associations were identified for alleles at the HLA-DRB1, HLA-DQA1, and HLA-DQB1 loci, including DRB1*03:01:01, DQA1*05:01:01, and DQB1*02:01:01, which conferred high risk, and DRB1*11:04:01, DQA1*05:05:01, and DQB1*03:01:01, which were protective. The DRB1*03:01:01~DQA1*05:01:01~DQB1*02:01:01 haplotype was most strongly associated with the risk of developing T1D, while DRB1*11:04-DQA1*05:05-DQB1*03:01 was the only haplotype that rendered protection against T1D. We also identified 66 amino acid positions across the HLA-DRB1, HLA-DQA1, and HLA-DQB1 genes that were significantly associated with T1D, including novel associations. These results validate and extend our knowledge on the associations between HLA genes and T1D in Kuwaiti children. The identified risk alleles, haplotypes, and amino acid variations may influence disease development through effects on HLA structure and function and may allow early intervention via population-based screening efforts.

Matched MeSH terms: Amino Acids/genetics
Fulltext Synthesis and physico-chemical properties of new tetraethylammonium-based amino acid chiral ionic liquids

Abdul Rahman MB, Jumbri K, Basri M, Abdulmalek E, Sirat K, Salleh AB

Molecules, 2010 Apr 05;15(4):2388-97.
PMID: 20428050 DOI: 10.3390/molecules15042388

This paper reports the synthesis of a series of new tetraethylammonium-based amino acid chiral ionic liquids (CILs). Their physico-chemical properties, including melting point, thermal stability, viscosity and ionic conductivity, have been comprehensively studied. The obtained results indicated that the decomposition for these salts proceeds in one step and the temperature of decomposition (T(onset)) is in the range of 168-210 degrees C. Several new CILs prepared in this work showed high ionic conductivity compared to the amino acid ionic liquids (AAILs) found in the literature.

Matched MeSH terms: Amino Acids/chemistry*

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