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B6db references: 5781017.

type Journal Article
authors Walker, J. B.; Walker, M.S.
title Streptomycin biosynthesis. Transamination reactions involving inosamines and inosadiamines
journal Biochemistry
ui 5781017
year (1969)
volume 8
pages 763-70
keywords Antibiotics/*biosynthesis
abstract In the biosynthesis of the streptidine moiety of streptomycin from myoinositol, the two nitrogen atoms on the cyclitol ring are introduced by transamination of inosose derivatives. The two transaminase activities have been separated on a Sephadex G-100 column; pyridoxal phosphate must be present during the separation to retain activity. The first transaminase to emerge from the column was L-glutamine- scyllo- inosose transaminase, which catalyzes the first reaction unique to streptidine biosynthesis. Scyllo -Inosamine, a known precursor of streptidine in cell-free preparations, is a product of this reaction. Enzyme preparations con- taining this activity also catalyze the following trans- aminations : scyllo -inosamine-jcy//o-inosose, 2-deoxy- streptamine-scylloinosose, scyllo-inosamine-myo-inosose-4(6), myo-inosamine-6- scyllo -inosose, streptamine- scyllo-inosose, L-alaninC-scyLLo-inosose, and scyllo- inosamine-pyruvate. The second amino group is added to the cyclitol ring in a reaction catalyzed by L-alanine- N-amidino-3- (or 5-) keto- scyllo -inosamine transaminase. N-Amidinostreptamine is a product of this reaction. L-Glutamate is the next most effective amino donor, followed by L-glutamine. Enzyme preparations containing this activity also catalyze the following transaminations: N-amidinostreptamine-pyruvate, N- amidinostreptamine-a-ketoglutarate, and N-amidino- streptamine-N-amidino-3- (or 5-) keto-scyllo-inosamine. At concentrations higher than those required for glutamine- scyllo-inosose transaminase, scyllo-inosose can serve as an amino acceptor from N-amidinostreptamine, and scyllo-inosamine as an amino donor to N-amidino-3- (or 5-) keto-scyllo-inosamine .
last changed 2017/11/03 18:30

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