Berruet L, Muller-Steffner H, Schuber F
Laboratoire de Chimie Bioorganique, UMR, Strasbourg-Illkirch, France.
Biochem Mol Biol Int. 1998 Nov;46(4):847-55.
Bovine spleen NAD+glycohydrolase, an ecto-enzyme closely related to CD38, catalyzes the conversion of NAD+ into ADP-ribose and cyclic ADP-ribose, a calcium-mobilizing metabolite. We have raised polyclonal antibodies against the native enzyme which on immunoblots revealed, besides the 32 kDa monomer, the presence of a stable dimeric form. This dimerization was shown to result from a spontaneous oxidative process involving the formation of one or several disulfide bond(s) sensitive to reducing agents such as 2-mercaptoethanol. The homodimeric oxidized enzyme, which was not detected during the early steps of the enzyme purification procedure, was catalytically active. Our results underline the differences, in terms of oligomerization and reactivity towards thiols, between CD38/NAD+glycohydrolases depending on their origin.
牛脾NAD⁺糖水解酶是一种与CD38密切相关的胞外酶，它催化NAD⁺转化为ADP - 核糖和环ADP - 核糖，后者是一种能动员钙的代谢产物。我们制备了针对天然酶的多克隆抗体，免疫印迹显示，除了32 kDa的单体之外，还存在一种稳定的二聚体形式。这种二聚化是由一个自发的氧化过程导致的，该过程涉及形成一个或几个对诸如2 - 巯基乙醇等还原剂敏感的二硫键。在酶纯化过程的早期步骤中未检测到的同源二聚体氧化酶具有催化活性。我们的结果强调了不同来源的CD38/NAD⁺糖水解酶在寡聚化和对硫醇的反应性方面的差异。
