논문 상세보기
pp.169-177
Glutamate로부터 glutamine으로 전환하는 효소인 glutamine synthetase는 cofactor로서 ATP를 요구하는 endergonic reaction이므로, glutamine 전환반응에 요되는 ATP의 효율적인 공급을 위해서 acetate kinase에 의한 ATP 생성계를 도입하였다. Glutamine synthetase의 효소윈으로 사용된 미생물은 glutamine synthetase의 활성이 강화된 E. coli K-12로 부터 사용하였으며, acetate kinase는 E. coli K-12로 부터 부분 정제하여 사용하였다. Acetate kinase에 의한 ATP 생성계를 도입한 glutamine 전환반응의 최적조건은 100mM glutamate, 100mM NH_4Cl, 50mM acetyl phosphate, 5mM ADP, 40mM MgCl_2, 300mM potassium phosphate buffer(pH7.5) 5mM MnCl_2, 70units/㎖ glutamine synthetase, 99units/㎖ acetate inase이었으며, 상기의 최족조건하에서 6시간째 98%의 최대전환율을 나타내었고 이때 생산량은 14.3g/ℓ 이었다.
The conversion of glutamate by glutamine synthetase is the endergonic reaction that demands ATP as its energy source. In order to supply efficiently ATP that is demanded in the conversion of glutamate to glutamine. the ATP-generating system by acetate kinase partially purified from Escherichia coli K-12 was coupled with glutamine synthetase partially purified E. coli K-12 Pgln6. The optinum conditions of the coupled reaction were investigated. As the result, the highest conversion of glutamate to glutamine was shown in the reaction mixture containing 100mM glutamate, 100mM NH_4Cl, 50mM acetyl phosphate, 5mM ADP, 40mM MgCl_2, 300mM potassium phosphate buffer(pH 7.5), 5mM MnCl_2. Under this condition, the most effective concentrations of enzyme were 70unit/m Q. glutamine synthetase and 99unit/㎖ acetate kinase. Under the optinum conditions, 98% of 100mM glutamate was converted to glutamine within 6 hours.
