Novel 7-N-(beta-alanyl)aminophenoxazin-3-one salts 27a-d have been synthesized and tested as chromogenic substrates for beta-alanyl aminopeptidase, which is present in Pseudomonas aeruginosa, the most common respiratory pathogen in patients with cystic fibrosis. The biological results show that 7-N-(beta-alanyl)amino-1-pentylphenoxazin-3-one trifluoroacetate salt 27a is a chromogenic substrate ...

Background: In the recent decades, the prevalence of nosocomial infections in neonates has grown and almost 21% of preterm neonates experience these kinds of infections. Some factors were proposed to have a protective effect against neonatal infections through promoting the development of the immune system of the newborn. This study aimed to evaluate the efficacy of oral glutamine supplementati...

1. An elastase-like enzyme in plasma of patients with acute pancreatitis was purified by DEAE-cellulose column chromatography and polyacrylamide-gel disc electrophoresis. 2. In this way 0.24 mg of purified enzyme with a specific activity of 3-94 succinyl-L-alanylL-alanyl-L-alanyl-p-nitroanilide units/mg of protein was obtained from 10 ml of plasma. 3. The purified material was homogeneous as as...

Teichoic acids (TAs) are major wall and membrane components of most gram-positive bacteria. With few exceptions, they are polymers of glycerol-phosphate or ribitol-phosphate to which are attached glycosyl and D-alanyl ester residues. Wall TA is attached to peptidoglycan via a linkage unit, whereas lipoteichoic acid is attached to glycolipid intercalated in the membrane. Together with peptidogly...

The steady state kinetic mechanism, molecular isotope exchange and the positional isotope exchange (PIX) reactions of D-alanyl-D-alanine ligase from Salmonella typhimurium have been studied. The kinetic mechanism has been determined to be ordered Ter-Ter from initial velocity and product inhibition experiments. The first substrate to bind is ATP followed by the addition of 2 mol of D-alanine. P...

The effects of tRNA, RF1 and RRF on trans-translation by tmRNA were examined using a stalled complex of ribosome prepared using a synthetic mRNA and pure Escherichia coli translation factors. No endoribonucleolytic cleavage of mRNA around the A site was found in the stalled ribosome and was required for the tmRNA action. When the A site was occupied by a stop codon, alanyl-tmRNA competed with R...

We present 13 (3)J, seven (2)J and four (1)J coupling constants (24 in all) calculated using B3LYP/D95** as a function of the φ and ψ Ramachandran dihedral angles of the acetyl(Ala)(3)NH(2) capped trialanine peptide over the entire Ramachandran space. With the exception of three of these J couplings, all show significant dependence upon both dihedral angles. For each J coupling considered, a tw...

The binding of Mg2+ to the ribitol teichoic acid of Staphylococcus aureus H walls was examined by equilibrium dialysis in solution and in the intact wall; the influence of alanyl ester groups on binding was determined. In solution the ribitol polymer had a lower affinity than did a glycerol teichoic acid and bound Mg2+ in the ratio Mg2+/P of 1:1. The presence of alanyl ester residues caused a d...

1. Studies have been made of jejunal absorption rates in vivo in the rat of the stereoisomers of alanylphenylalanine, leucyl-leucine and glycyltryptophan. Absorption rates of L-alanyl-L-phenylalanine were about 200 times those of D-alanyl-D-phenylalanine, L-leucyl-L-leucine about 24 times those of the DD-isomer, and glycyl-L-tryptophan 5 times those of glycyl-D-tryptophan. The mixed DLand LD-is...