大肠杆菌K12突变体合成维生素B6及4'-脱氧吡哆醇的作用

Synthesis of vitamin B6 by a mutant of Escherichia coli K12 and the action of 4'-deoxypyridoxine.

作者信息

Scott T A, Hockney R C

出版信息

J Gen Microbiol. 1979 Feb;110(2):285-9. doi: 10.1099/00221287-110-2-285.

Abstract

Mutants of Escherichia coli K12 blocked in the oxidation of pyridoxine 5'-phosphate ('Oxidase' mutants) excreted pyridoxine at an initial rate of 19 pmol h-1 (10(8) bacteria)-1, i.e.0.6 nmol h-1 (mg dry wt)-1, when starved for pyridoxal. Glycolaldehyde, L-phosphoserine, DL-serine and, to a lesser extent, L-leucine stimulated the rate of pyridoxine excretion, but there was no significant stimulation by 2'-hydroxypyridoxine. 4'-Deoxypyridoxine inhibited or stimulated growth of the "Oxidase' mutant, depending on the relative concentrations of added pyridoxal and 4'-deoxypyridoxine. It was concluded that stimulation of growth by 4'-deoxypyridoxine was due to its conversion to pyridoxal.

摘要

在5'-磷酸吡哆醇氧化过程中受阻的大肠杆菌K12突变体（“氧化酶”突变体），在缺乏吡哆醛饥饿状态下，以19皮摩尔·小时⁻¹（10⁸个细菌）⁻¹的初始速率排泄吡哆醇，即0.6纳摩尔·小时⁻¹（毫克干重）⁻¹。乙醇醛、L-磷酸丝氨酸、DL-丝氨酸，以及程度较轻的L-亮氨酸刺激了吡哆醇的排泄速率，但2'-羟基吡哆醇没有显著刺激作用。4'-脱氧吡哆醇抑制或刺激“氧化酶”突变体的生长，这取决于添加的吡哆醛和4'-脱氧吡哆醇的相对浓度。得出的结论是，4'-脱氧吡哆醇对生长的刺激是由于其转化为吡哆醛。