Moss J, Stanley S J, Watkins P A
J Biol Chem. 1980 Jun 25;255(12):5838-40.
An NAD- and guanidine-dependent ADP-ribosyltransferase has been purified more than 500,000-fold from turkey erythrocytes with an 18% yield. The enzyme in the 100,000 X g supernatant fraction was bound to phenyl-Sepharose, eluted with 50% propylene glycol, and further purified by sequential chromatographic steps on carboxymethylcellulose, NAD-agarose and concanavalin A-agarose. The transferase was specifically eluted from concanavalin A-agarose with alpha-methylmannoside. The enzymatic activity was extremely labile following the first purification step. Both propylene glycol and NaCl stabilized the transferase; significant increases in enzyme recovery were obtained by conducting the NAD- and concanavalin A-agarose chromatography in buffer containing propylene glycol. The purified protein exhibits one predominant protein band on SDS-polyacrylamide gels with an estimated molecular weight of 28,300. On Ultrogel AcA54 chromatography, single coincident peaks of ADP-ribosyltransferase activity and protein were observed. Enzyme activity was independent of DNA; the highly purified transferase was inhibited by thymidine, nicotinamide, and theophylline. The specific activity of the purified enzyme (350 mumol of ADP-ribose transferred from NAD to arginine methyl estermin-1mg-1) is comparable to that reported for purified NAD glycohydrolases and poly(ADP-ribosyl)transferases.
一种依赖烟酰胺腺嘌呤二核苷酸(NAD)和胍的ADP核糖基转移酶已从火鸡红细胞中纯化出来,纯化倍数超过50万倍,产率为18%。100,000×g上清液中的酶与苯基琼脂糖结合,用50%丙二醇洗脱,然后通过在羧甲基纤维素、NAD琼脂糖和伴刀豆球蛋白A琼脂糖上的连续色谱步骤进一步纯化。该转移酶用α-甲基甘露糖苷从伴刀豆球蛋白A琼脂糖上特异性洗脱。在第一步纯化后,酶活性极不稳定。丙二醇和氯化钠都能使转移酶稳定;通过在含有丙二醇的缓冲液中进行NAD琼脂糖和伴刀豆球蛋白A琼脂糖色谱,酶回收率显著提高。纯化后的蛋白质在SDS聚丙烯酰胺凝胶上呈现一条主要蛋白带,估计分子量为28,300。在Ultrogel AcA54色谱上,观察到ADP核糖基转移酶活性和蛋白质的单一重合峰。酶活性与DNA无关;高度纯化的转移酶受到胸苷、烟酰胺和茶碱的抑制。纯化酶的比活性(从NAD转移到精氨酸甲酯的350μmol ADP核糖/mg-1)与报道的纯化NAD糖水解酶和聚(ADP核糖)转移酶的比活性相当。