Serine Transhydroxymethylase

摘要: Abstract A number of substrate analogues serine transhydroxymethylase were tested as competitive inhibitors and substrates. Our previous results show that l-serine, l-threonine, allothreonine, d-alanine serve In this study, we found threo- erythro-β-phenylserine cleaved to benzaldehyde glycine. Tetrahydrofolate was not required for reaction. Substrate which contained an amino group adjacent a carboxyl, phosphonate, or sulfonate bound by the enzyme. Analogues lacked either carboxyl acid had little if any affinity active site. The only exceptions several sulfhydryl compounds. Several d-amino acids with d-cysteine being most effective. This shows configuration around α-carbon is critical binding. variation Vmax Km pH allothreonine determined. Both change from 5.8 7.6. However, anion binding site on enzyme pK 6.2 found. showed specificity anions all serving inhibitors. enzyme-glycine complex exhibits absorption maxima at 343, 425, 495 mµ. equilibrium between complexes absorbing 343 425 mµ be sensitive both temperature pH. 6.9 involved. sensitivity observed due in part large increase entropy, suggests conformational changes protein are also involved interconversion complexes.