Young D, Tallman M, Landy K, Young T, Lukas D, Lewis B, McGuinness E
UMDNJ, School of Dentistry, Newark 07103, USA.
Biochem Biophys Res Commun. 1998 Jun 9;247(1):154-8. doi: 10.1006/bbrc.1998.8557.
The ocular lens displays a significant amount of NADP(H) dependent metabolic traffic, but the origin of this cofactor has not been established. Size exclusion chromatography of bovine lens crude extract on a Sephacryl S300-HR column fitted with an eluate concentrator revealed two bands with NAD kinase activity, based on enzymatic cycling with signal amplification of the column fractions using a Cobas-Fara II centrifugal fast analyzer. Ve/Vo ratios from the chromatographic runs suggest that the relative molecular weight values lie within the ranges 8.91-3.98 x 10(5) and 2.04-1.26 x 10(5), respectively, for these two bands. An approximately 10-fold enhancement of enzyme activity over the crude fraction is realized from the chromatography step. Results point to NAD kinase as the source generator of this anchoring and linking cofactor for the oxidative stress and pentose phosphate enzyme systems, respectively.
晶状体表现出大量依赖烟酰胺腺嘌呤二核苷酸磷酸（还原型）（NADP(H)）的代谢通量，但这种辅因子的来源尚未确定。在配备洗脱液浓缩器的Sephacryl S300-HR柱上对牛晶状体粗提物进行尺寸排阻色谱分析，基于使用Cobas-Fara II离心快速分析仪对柱级分进行信号放大的酶循环，发现有两条具有NAD激酶活性的条带。色谱运行的Ve/Vo比表明，这两条带的相对分子量值分别在8.91 - 3.98×10⁵和2.04 - 1.26×10⁵范围内。通过色谱步骤，酶活性比粗级分提高了约10倍。结果表明，NAD激酶分别是氧化应激和磷酸戊糖酶系统中这种锚定和连接辅因子的来源生成器。
