31P NMR investigations on free and enzyme bound thiamine pyrophosphate.
Pyruvate decarboxylase (PDC) contains thiamine pyrophosphate (TPP) and Mg2+ as cofactors. 31P NMR studies with PDC in the presence of added Mn2+ reveal the pyrophosphate moiety of TPP to be a nonaccessible area for the external Mn2+ and thus proving the Mg-P-complex (taking part in the binding of the coenzyme to the protein) to be a nonaccessible area for the medium. Glyoxylic acid, acting as an inhibitor of PDC by forming a noncleavable bond with the catalytic center of TPP causes a steric immobilization of the coenzyme indicated by a line broadening of the pyrophosphate moiety.
Flatau
S
S
Dept of Biochemistry, University of Halle, GDR.
Fischer
G
G
Kleinpeter
E
E
Schellenberger
A
A
D002262:Carboxy-Lyases / Q000378:metabolism*; D008024:Ligands; D008274:Magnesium / Q000494:pharmacology; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008345:Manganese / Q000494:pharmacology; D010758:Phosphorus; D011485:Protein Binding; D011767:Pyruvate Decarboxylase / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000201:enzymology; D013835:Thiamine Pyrophosphate / Q000378:metabolism*
D008024:Ligands; D010758:Phosphorus; D008345:Manganese; D002262:Carboxy-Lyases; D011767:Pyruvate Decarboxylase; D008274:Magnesium; D013835:Thiamine Pyrophosphate