Kimura K, Goto T
J Biochem. 1975 Feb;77(2):415-20. doi: 10.1093/oxfordjournals.jbchem.a130740.
Dihydrodipicolinate reductase in Bacillus subtilis PCI 219 had FMN as a prosthetic group, and the hydrogen transfer pathway is considered to be NADPH yields FMN yields dihydrodipicolinate. Linewaver-Burk plots of the reciprocal of the activity against the reciprocal of the concentration of either of the two substrates, dihydrodipocolinate and NADPH, are consistent with a reaction mechanism involving interconversion of two free forms of the enzyme by the two substrates. The Km values obtained from the secondary plots are 0.77 mM for dihydrodipicolinate and 72 muM for NADPH. Inhibition by dipicolinate is competitive with NADPH and noncompetitive with dihydrodipicolinate, and shows positive cooperativity. The possible metabolic role of the reductase in sporulating Bacillus subtilis is discussed in connection with regulation of the biosyntheses of dipicolinate and diaminopimelate.
枯草芽孢杆菌PCI 219中的二氢二吡啶甲酸还原酶以黄素单核苷酸（FMN）作为辅基，并且氢转移途径被认为是烟酰胺腺嘌呤二核苷酸磷酸（NADPH）产生FMN，进而产生二氢二吡啶甲酸。以两种底物（二氢二吡啶甲酸和NADPH）中任一种浓度的倒数为横坐标，以活性的倒数为纵坐标绘制的林-贝氏图，与涉及两种底物使酶的两种游离形式相互转化的反应机制一致。从二级图获得的米氏常数（Km）值，二氢二吡啶甲酸为0.77 mM，NADPH为72 μM。吡啶甲酸的抑制作用对NADPH是竞争性的，对二氢二吡啶甲酸是非竞争性的，并且表现出正协同性。结合二吡啶甲酸和二氨基庚二酸生物合成的调控，讨论了该还原酶在枯草芽孢杆菌芽孢形成过程中可能的代谢作用。
