The antisickling effect of dried Aristeus antennatus was investigated to ascertain the efficacy extract sample inhibit polymerization sickle cell haemoglobin (HbSS), and improve Fe2+/Fe3+ ratio blood. first dried, ground into powder soaked in chloroform defat it order produce fat soluble fraction (filtrate). defatted residue air-dried later methanol for 24 hours obtain fraction. fractions (FAS)...

Sulfhydryl reagents, as well as mild hydrogen peroxide oxidation, do not inhibit the activity of yeast phosphoglycerate kinase, indicating that the single thiol group and 3 methionine residues present in the enzyme are not essential for activity. Nitration of phosphoglycerate kinase by tetranitromethane inhibits the enzyme by reaction with a single tyrosine residue. Substrates provide partial p...

The inhibition of anion transport by dinitrophenylation of the red cell membrane is brought about by the modification of a single lysine residue located on the 17-kDa segment of the band 3 protein. This residue is identical with Lys a, which is also capable of reacting with one of the two isothiocyanate groups of 4,4'-diisothiocyano dihydro-stilbene-2,2'-disulfonate (H2DIDS). The rate of reacti...

Analogues of Wysine-vasopressin in which the carboxamide groups on the glutamine and asparagine residues at positions 4 and 5 are replaced individually by hydrogen have been synthesized by the p-nitrophenyl ester method of peptide synthesis and tested for some of the pharmacological activities characteristic of this pressor-antidiuretic hormone of the posterior pituitary gland. The 4-decarboxam...

ALA exhibits this activity in both the reduced and oxidated forms. Lipoic acid is a racemic mixture. The redox couple α-lipoic/dihydrolipoic acid containing the R-enantiomer is covalently bound to a lysine residue, forming an essential lipoamide, which functions as a co-enzyme for the E2 subunit of four multi-enzymatic mitochondrial complexes, for example pyruvate dehydrogenase [1-6]. After adm...

Abstract Despite recent interests in developing lysine‐targeting covalent inhibitors, no general approach is available to create such compounds. We report herein a develop cell‐active inhibitors of protein kinases by targeting the conserved catalytic lysine residue using key SuFEx and salicylaldehyde‐based imine chemistries. validated strategy successfully (irreversible reversible) against BCR‐...

Biotin carboxylase from Escherichia coli catalyzes the ATP-dependent carboxylation of biotin and is one component of the multienzyme complex acetyl-CoA carboxylase, which catalyzes the committed step in long-chain fatty acid synthesis. For the carboxylation of biotin to occur, biotin must be deprotonated at its N1' position. Kinetic investigations, including solvent isotope effects and enzyme i...

STAT92E is an essential transcription factor in Drosophila melanogaster for the development of several organs and the immune system. The JAK/STAT pathway employs different evolutionary conserved regulatory mechanisms to control biological processes. Numerous transcription factors in both mammals and invertebrates have been shown to be either activated or inhibited by a covalent modification wit...

Uroporphyrinogen III synthase purified from rat liver is a monomer of Mr 36,000 by gel filtration and 28,000 by SDS/polyacrylamide-gel electrophoresis. The enzyme exists in two interconvertible forms separable on h.p.l.c. Both forms of the enzyme could be renatured with full activity after SDS/polyacrylamide-gel electrophoresis, demonstrating the absence of a reversibly bound cofactor. The enzy...

Monoubiquitylation of the homotrimeric DNA sliding clamp PCNA at lysine residue 164 (PCNA(K164)) is a highly conserved, DNA damage-inducible process that is mediated by the E2/E3 complex Rad6/Rad18. This ubiquitylation event recruits translesion synthesis (TLS) polymerases capable of replicating across damaged DNA templates. Besides PCNA, the Rad6/Rad18 complex was recently shown in yeast to ub...