Abe S, Hayasaka K, Narisawa K, Tada K, Okada G, Koyama H, Kurosu S, Kudoh M, Matsushita K
Enzyme. 1987;37(4):182-8. doi: 10.1159/000469260.
We have studied adenine phosphoribosyltransferase (APRT) in the hemolysates from the families of 2,8-dihydroxyadenine urolithiasis associated with partial deficiency of APRT (the Japanese type) and complete deficiency of APRT (the null type). The APRT in the control subjects was found to be heat-stable at the physiological concentration of phosphoribosylpyrophosphate (PRPP), which was close to the value of its Km for PRPP. The APRT in the Japanese type showed 10 times higher Km values for PRPP and needed a comparably increased level of PRPP for stability in vitro. No change in red cell PRPP was found in the Japanese type of APRT deficiency. The content of APRT enzyme protein was decreased in the hemolysates of the Japanese type, probably due to its lability at the level of PRPP present in the cells. The heterozygote of the null type also had labile enzyme molecules at the physiological PRPP concentration.
我们研究了来自2,8 - 二羟基腺嘌呤尿石症患者家族的溶血产物中的腺嘌呤磷酸核糖转移酶（APRT），这些家族中存在APRT部分缺乏（日本型）和APRT完全缺乏（无效型）的情况。发现在磷酸核糖焦磷酸（PRPP）的生理浓度下，对照受试者中的APRT对热稳定，该生理浓度接近其对PRPP的Km值。日本型中的APRT对PRPP的Km值高10倍，并且在体外需要相当程度升高的PRPP水平来维持稳定。在日本型APRT缺乏症患者中未发现红细胞PRPP有变化。日本型的溶血产物中APRT酶蛋白含量降低，这可能是由于其在细胞内存在的PRPP水平下不稳定所致。无效型的杂合子在生理PRPP浓度下也具有不稳定的酶分子。
