Human tryptophanyl-tRNA synthetase resembles its counterpart in Escherichia coli in quaternary structure (alpha2), but differs in molecular weight, amino acid composition, the number of thiol groups, and the relationship of the thiol groups to enzyme activity. Nevertheless, one of the thiol groups resides in a heptapeptide sequence homologous to a heptapeptide sequence containing a thiol group ...

Objective: We aimed to investigate the relationship between umblical coiling index and thiol/disulfide balance in SGA newborns compare with AGA newborns.
 Material Methods: Fetal umbilical cord serum samples were collected during labour homeostasis was measured. After birth, cords parameters examined including, length, number of coils, index.
 Results: Significant decrease native thio...

The aim of this study was to determine dynamic thiol-disulphide homeostasis (TDH) parameters and ischemia modified albumin (IMA) levels in calves with neonatal diarrhea compare healthy controls. A total 50 were included the study. There 25 both groups. Serum native thiol, disulfide IMA measured using new methods. Native thiol (P=0.025) (P=0.041) values decreased significantly compared control g...

The influence of oxidation of membrane thiol groups on lysosomal proton permeability was studied by measuring lysosomal pH with FITC-conjugated dextran, determining the membrane potential with 3,3'-dipropylthiadicarbocyanine iodide and monitoring their proton leakage with p-nitrophenol. Residual membrane thiol groups were measured with 5,5'-dithiobis-(2-nitrobenzoic acid). The lysosomal membran...

The reactivities of the two cysteine thiol groups of calf thymus F3 histone were investigated using 5,5'-dithiobis-[2- nitrobenzoic acid], (DTNB). In isolated histone, both thiol groups were available for reaction. However, analysis of reaction profiles of native deoxyribonucleohistone, (DNH), in various solvent conditions, together with gel electrophoresis studies of DNH modified with DTNB, sh...

1. The inhibitory effects of iodoacetate, iodoacetamide, p-hydroxymercuribenzoate and sarkomycin were studied in a partially purified preparation of deoxyribonucleic acid nucleotidyltransferase from Landschutz ascites-tumour cells. All of these agents inhibited the activity of the enzyme, and it was shown that the inhibition exerted by the last three compounds obeyed non-competitive kinetics. 2...