Purification and Properties of the B Component of Escherichia coli Tryptophan Synthetase

摘要: SUMMARY The procedure used to purify the B subunit of Escherichia coli tryptophan synthetase is described. purified protein ap- pears nearly homogeneous in ultracentrifuge and starch gel electrophoresis. Its sedimentation coefficient was determined be 5.0X, a molecular weight 108,000 calculated from experiments. Pyridoxal phosphate has been established as cofactor enzyme; approximately 2 moles are bound each mole protein. re- solved into an apoenzyme which catalytically inactive pyridoxal phosphate-dependent conversion indole trypto- phan but retains its capacity aid A indolyl- glycerol cleavage. Treatment with sodium borohy- dride results more active than native assisting cleavage indolylglyc- erol phosphate. calculation based on specific activities weights subunits their complex suggests that AB consists molecules 1 molecule. REFERENCES