Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Pyruvic Acid”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 361 records · Page 20Linked to original sources
PubMed1980

Studies on the kinetics and stoichiometry of inactivation of Pseudomonas omega-amino acid:pyruvate transaminase by gabaculine.

A homogeneous pyruvate-requiring omega-amino acid transaminase from Pseudomonas species F-126 has been examined for its behavior with gamma-aminobutyrate (GABA) as omega-amino acid substrate and for its susceptibility to the cyclic dihydroaromatic GABA analogue, gabaculine, a known suicide substrate for alpha-ketoglutarate-requiring GABA transaminases (Biochemistry 16, 4604-4610, 1977). One isomer of DL-gabaculine serves as a completely efficient titrant (no product molecules released) for this omega-amino acid transaminase by the anticipated mechanism of bound pyridoxal 5'-phosphate (PLP) derivitization. Stoichiometric titration with [2-3H]gabaculine reveals full inactivation at 0.45 labels/enzyme tetramer (see below), consistent with the subsequent demonstration that there is only 0.45 PLP molecule, bound as phenylhydrazine-titratable aldehyde form, per tetramer. Spectroscopic monitoring of inactivation also agrees with formation, on full inactivation, of 0.45 mol of m-anthranilyl-PNP adduct as the species quantitatively responsible for enzyme inactivation. Incubation of enzyme with excess PLP at 60 degrees C allows loading of enzyme with coenzyme to an average level of approximately 1 PLP/subunit, but even in this case activity is only increased up to 1.5-fold, and 1 to 1.5 molecules of gabaculine/tetramer cause complete inactivation. These data may indicate negative cooperativity between subunits.

Cyclohexanecarboxylic Acids↗