Amino acids are one of the most important molecules in living organisms, and most of them have a chiral carbon at the a-position. In the higher animals, a large part of the naturally occurring amino acids is the L-form, and the stereoisomers (D-amino acids) had been believed to be rare. However, especially in the last decade, several D-amino acids were found in mammals including humans, and the...

The role of thymus in antibody responses to a series of four synthetic polypeptide immunogens of the general formula multi-copoly(Tyr,Glu)-poly(Pro)-poly(Lys) was investigated as a function of the optical activity of the amino acids composing their structure. Irradiated nonthymectomized and thymectomized SJL mice were injected with thymocytes, marrow cells, or a mixture of both. Each group of r...

d/l-Hybrid peptides are an attractive class of molecular modality because they able to exhibit high proteolytic stability and unique structural diversity which cannot be accessed by those consisting only proteinogenic l-amino acids. Despite such expectation, it has not been possible devise de novo d/l-hybrid capable disrupting the function a protein target(s) due lack effective method that reli...

The ability to grow on media containing certain D-amino acids as a sole nitrogen source is widely utilized to differentiate Cryptococcus gattii from C. neoformans. We used the C. neoformans H99 and C. gattii R265 strains to dissect the mechanisms of D-amino acids utilization. We identified three putative D-amino acid oxidase (DAO) genes in both strains and showed that each DAO gene plays differ...

The aim of the present study was to assess whether near infrared reflectance spectroscopy (NIRS) and regression equations are the practical and accurate approach of nutritional assessment of common feedstuffs. Therefore two experiments were conducted to study the effect of amino acid determination methods on broiler performance. In experiment I, two hundred thirty four male Ross broiler chicks ...

D-Amino acids administered to animals are absorbed by the intestine and transported through the blood-stream to solid tissues where they are oxidized in vivo by D-amino acid oxidase and D-aspartate oxidase to produce the same compounds they do in vitro; i.e. NH3, H2O2, and the keto acid corresponding to the amino acid ingested. In the liver and kidneys of the animals, an inverse relationship ex...

securigera securidaca (l.) degen & dorfl grows in different parts of iran. the seeds of the species are used in iranian folk medicine as an anti-diabetic agent. many studies have established hypoglycemic effects of amino acids and in the present investigation, amino acids of securigera securidaca seeds have been evaluated. the ground seeds were extracted using petroleum ether, hot ethanol a...

The soil bacterium Bacillus subtilis forms biofilms on surfaces and at air-liquid interfaces. It was previously reported that these biofilms disassemble late in their life cycle and that conditioned medium from late-stage biofilms inhibits biofilm formation. Such medium contained a mixture of D-leucine, D-methionine, D-tryptophan, and D-tyrosine and was reported to inhibit biofilm formation via...

It has been generally assumed that the role of D-amino acids in bacterial physiology is rather limited. However, recent new evidence demonstrated that millimolar concentrations of noncanonical D-amino acids are synthesized and released to the environment by bacteria from diverse phyla. These D-amino acids help bacteria adapt to environmental challenges by modulating the structure and compositio...

As natural plant growth stimulators, amino acids are widely used to improve the yield and quality of crops. Change in enzymes activities of N assimilation (NR, NiR and GS), residual nitrate (NO3-), soluble protein content, and yield of spinach and lettuce plants were investigated under replacing 20% nitrate-N in the nutrient solution by L-glycine and blood meal amino acids. Seeds of the mention...