Serine:glyoxylate aminotransferase from the seedlings of rye (Secale cereale L.).
Serine:glyoxylate aminotransferase (EC 2.6.1.45) from green parts of 7-day-old rye seedlings was purified 600-fold. Specific activity of the purified enzyme against L-serine and glyoxylate as substrates was 53.2 mumol/mg protein per minute at 30 degrees C. The enzyme activity with L-alanine or L-asparagine and glyoxylate, or with L-asparagine and hydroxypyruvate was 20% that with L-serine and glyoxylate as the amino group acceptor, whereas with L-alanine or glycine and hydroxypyruvate it was 10% of that value. The reaction rate with pyruvate and L-asparagine, glycine or L-serine was very low. The enzyme was stabilized by the presence of sucrose, pyridoxal phosphate and 2-mercaptoethanol. Molecular sieving of the native enzyme on Sephacryl S-300 gel gave Mr values of 91,200 and 85,000, whereas the molecular weight estimated by SDS-polyacrylamide gel electrophoresis was 43,000, indicating the dimeric structure of the enzyme.
Paszkowski
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Department of Biochemistry, Institute of Plant Biology University of Agriculture, Warsaw, Poland.
Niedzielska
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D004591:Electrophoresis, Polyacrylamide Gel; D004795:Enzyme Stability / Q000187:drug effects; D006038:Glyoxylates / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D008623:Mercaptoethanol / Q000494:pharmacology; D008970:Molecular Weight; D011732:Pyridoxal Phosphate / Q000494:pharmacology; D011773:Pyruvates / Q000494:pharmacology; D019289:Pyruvic Acid; D012434:Secale / Q000187:drug effects / Q000201:enzymology*; D012639:Seeds / Q000187:drug effects / Q000201:enzymology*; D012694:Serine / Q000378:metabolism; D013379:Substrate Specificity / Q000187:drug effects; D013395:Sucrose / Q000494:pharmacology; D000637:Transaminases / Q000378:metabolism*
D006038:Glyoxylates; D011773:Pyruvates; D012694:Serine; D013395:Sucrose; D011732:Pyridoxal Phosphate; D008623:Mercaptoethanol; D019289:Pyruvic Acid; D000637:Transaminases; C022636:serine-glyoxylate aminotransferase; C031150:glyoxylic acid