Daubner S C, Schrimsher J L, Schendel F J, Young M, Henikoff S, Patterson D, Stubbe J, Benkovic S J
Biochemistry. 1985 Dec 3;24(25):7059-62. doi: 10.1021/bi00346a006.
Three activities on the pathway of purine biosynthesis de novo in chicken liver, namely, glycinamide ribonucleotide synthetase, glycinamide ribonucleotide transformylase, and aminoimidazole ribonucleotide synthetase, have been found to reside on the same polypeptide chain. Three diverse purification schemes, utilizing three different affinity resins, give rise to the same protein since the final material has identical specific activities for all three enzymatic reactions and a molecular weight on sodium dodecyl sulfate gels of about 110 000. A single antibody preparation precipitates all three activities and binds to the multifunctional protein obtained by two methods in Western blots. Partial chymotryptic digestion of the purified protein gives rise to two fragments, one possessing glycinamide ribonucleotide synthetase activity and the other containing glycinamide ribonucleotide transformylase activity.
鸡肝中嘌呤从头合成途径上的三种活性，即甘氨酰胺核糖核苷酸合成酶、甘氨酰胺核糖核苷酸转甲酰酶和氨基咪唑核糖核苷酸合成酶，已被发现存在于同一条多肽链上。利用三种不同的亲和树脂的三种不同纯化方案得到了相同的蛋白质，因为最终产物对所有三种酶促反应具有相同的比活性，并且在十二烷基硫酸钠凝胶上的分子量约为110000。单一抗体制剂沉淀所有三种活性，并在蛋白质印迹中与通过两种方法获得的多功能蛋白结合。对纯化蛋白进行部分胰凝乳蛋白酶消化产生两个片段，一个具有甘氨酰胺核糖核苷酸合成酶活性，另一个含有甘氨酰胺核糖核苷酸转甲酰酶活性。
