Using cytidine 2':3' cyclic monophosphate as a substrate, Km and k(cat) of ribonuclease-A in the presence of different concentrations of D-amino acids (Ala, Ser, Pro and Lys) and their L-isomers were measured at pH 6.0 and 25 degrees C. These kinetic parameters remained unchanged in the presence and absence of D-and L-amino acids. This is the first experimental evidence showing that D-amino aci...

A transaminase (aminotransferase, EC 2.6.1) fraction was partially purified from shoot tips of pea (Pisum sativum L. cv. Alaska) seedlings. With alpha-ketoglutarate as co-substrate, the enzyme transaminated the following aromatic amino acids: d,l-tryptophan, d,l-tyrosine, and d,l-phenylalanine, as well as the following aliphatic amino acids: d,l-alanine, d,l-methionine, and d,l-leucine. Of othe...

OBJECTIVE Pseudomonas aeruginosa, a known biofilm-forming organism, is an opportunistic pathogen that plays an important role in chronic otitis media, tracheitis, cholesteatoma, chronic wounds, and implant infections. Eradication of biofilm infections has been a challenge because the biofilm phenotype provides bacteria with a protective environment from the immune system and antibiotics; thus, ...

Photosynthesis in the surface ocean converts atmospheric CO2 into organic particles, with fraction sinking to depth representing a major part of ocean's biological pump. Although particles are known be altered by attached-bacteria during transit, most prior geochemical data indicated only minor replacement plankton-derived bacterial material. We exploit bacteria-specific biomarkers (d-amino aci...

Like many biological compounds, proteins are found primarily in their homochiral form. However, homochirality is not guaranteed throughout life. Determining chiral proteinogenic sequence a complex analytical challenge. This because certain d-amino acids contained play role human health and disease. the case, for example, with d-Asp elastin, ?-amyloid ?-crystallin which, respectively, have an ac...

In lb is research, adsorption of some amino acids and their complenation with manganese (II) ion on carbonnanotube (MWCNT) by using of four relations Langmuir, Freundlich. Temkin and Harkins -Jura imitherms wasinvestigated. From this relations. Freudlich and Temkin relations predict good equilibrium diagram in, isothermcondition. we could compute the theoretical constants by excel software. Hy ...

it has been reported that neurons in the vl pag projecting to nucleus raphe magnus (nrm) utilize excitatory amino acids as neurotransmitter. this projection plays an important role in the descending pain modulatory system. in order to determine the role of this pathway in pain perception, male rats received unilateral injection of ibotenic acid stereotaxically. for lesioning vl pag, unilateral ...

the adsorption of a number of amino acids on a defected single-walled carbon nanotube (swcnt) isinvestigated by using the density-functional theory (dft) calculations. the adsorption energies andequilibrium distances are calculated for various configurations such as amino acid attaching to defectsites heptagon, pentagon and hexagon in defective tube and also for several molecular orientationswi...

fish larvae have a high requirement of amino acid (aa) for energy production and growth. this study was aimed to increase knowledge of aa profile during feral carp larval ontogeny and estimate larval aa requirements. larvae were collected randomly at 1, 3, 7, 11, 15, 19, 26 and 33 days post hatch for growth and aa analysis. the composition of total aa changed significantly during ontogeny. the ...