Ghangas G S, Milman G
Proc Natl Acad Sci U S A. 1975 Oct;72(10):4147-50. doi: 10.1073/pnas.72.10.4147.
We have developed a sensitive radioimmunoassay capable of detecting and quantitating 20 ng of hypoxanthine phosphoribosyltransferase (EC 2.4.2.8; IMP:pyrophosphate phosphoribosyltransferase) protein. For this assay, hypoxanthine phosphoribosyltransferase from human erythrocytes was iodinated with 125I under mild conditions using hydrogen peroxide and lactoperoxidase attached to Sepharose-4B. Antisera prepared against homogeneous human hypoxanthine phosphoribosyltransferase precipitates the iodinated enzyme as effectively as the unlabeled enzyme. The radioimmunoassay has been used to look for hypoxanthine phosphoribosyltransferase crossreacting material in hemolysates from sixteen different patients with a marked genetic deficiency of this enzyme characteristic of the Lesch-Nyhan syndrome. Fifteen hemolysates contained no detectable (less than 1% of normal) crossreacting material. One hemolysate contained a normal amount of crossreacting material. Hypoxanthine phosphoribosyltransferase from this patient (E.S.) has been shown to be a Km mutant enzyme.
我们开发了一种灵敏的放射免疫测定法,能够检测和定量20纳克的次黄嘌呤磷酸核糖转移酶(EC 2.4.2.8;IMP:焦磷酸磷酸核糖转移酶)蛋白。对于该测定法,在温和条件下,使用附着于琼脂糖-4B的过氧化氢和乳过氧化物酶,将来自人红细胞的次黄嘌呤磷酸核糖转移酶用125I进行碘化。针对纯合人次黄嘌呤磷酸核糖转移酶制备的抗血清沉淀碘化酶的效果与未标记的酶一样有效。该放射免疫测定法已用于在16名患有莱施-奈恩综合征特征性该酶明显遗传缺陷的不同患者的溶血产物中寻找次黄嘌呤磷酸核糖转移酶交叉反应物质。15份溶血产物中未检测到(低于正常的1%)交叉反应物质。一份溶血产物含有正常量的交叉反应物质。已证明该患者(E.S.)的次黄嘌呤磷酸核糖转移酶是一种Km突变酶。