The origin of homochirality of l-amino acids has long been a mystery. Aminoacylation of tRNA might have provided chiral selectivity, since it is the first process encountered by amino acids and RNA. An RNA minihelix (progenitor of the modern tRNA) was aminoacylated by an aminoacyl phosphate oligonucleotide that exhibited a clear preference for l- as opposed to d-amino acids. A mirror-image RNA ...

Discussions are made concerning realistic mechanisms for the origin of L-amino acids in the biosphere. As the most plausible mechanism, it is proposed that a mixture of racemic amino acids in the prebiotic sea caused spontaneous and effective optical resolution through self crystallization, even if asymmetric synthesis of a single amino acid has never occurred without the aid of an optically ac...

Amino acids are important components for peptides and proteins and act as signal transmitters. Only L-amino acids have been considered necessary in mammals, including humans. However, diverse D-amino acids, such as D-serine, D-aspartate, D-alanine, and D-cysteine, are found in mammals. Physiological roles of these D-amino acids not only in the nervous system but also in the endocrine system are...

D-amino acids are valuable building blocks for the synthesis of biologically active compounds and pharmaceuticals. The asymmetric chiral amino from prochiral ketones using stereoselective enzymes is a well-known but far exhausted approach large-scale production. Herein, we investigated pyridoxal-5′-phosphate-dependent acid transaminase Haliscomenobacter hydrossis as potential biocatalyst enzyma...

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 ...

L-amino acids bind preferentially to their D-codons, but almost nothing is known about whether D-amino acids correspondingly prefer L-codons, or how codon directionality affects amino acid binding. To investigate these issues, two D-RNA-oligonucleotides having inverse base sequences (D-CGUA and D-AUGC) and their corresponding L-RNA-oligonucleotides (L-CGUA and L-AUGC) were synthesized and their...

The aim of the present research is to investigate the profile of amino acid of Chlorella vulgaris supplemented with some plant amino acid and oil extracts. The bioactive oil and amino acid from four Iranian medicinal plants, namely Oliveria decumbens, Thymus kotschyanus, Trachyspermum ammi, and Zataria multiflora were obtained. The LC-MS / MS analysis demonstrated that the major amino acids com...