Immunochemical studies on cultured fibroblasts from patients with inherited methylmalonic acidemia.
Immunochemical studies on cultured fibroblasts from patients with inherited methylmalonic acidemia.
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对遗传性甲基丙二酸血症患者培养的成纤维细胞的免疫化学研究。
DOI：
10.1073/pnas.78.12.7737
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发表时间：
1981
影响因子：
11.1
通讯作者：
Rosenberg,LE
中科院分区：
文献类型：
--
作者：
Kolhouse,JF;Utley,C;Fenton,WA;Rosenberg,LE
我们开发了一种放射免疫测定法，定量测定与人甲基丙二醇-辅酶a（甲基丙二醇-辅酶a -辅酶a -羰基mutase， EC 5.4.99.2）发生免疫化学交叉反应的物质，并将该测定法应用于对照组和32名甲基丙二酸血症患者的成纤维细胞提取物，这些患者是由于遗传性变化酶活性不足而导致的。四条对照系平均每mg细胞蛋白含有237 ng的交叉反应物质（CRM）（范围为193-297 ng/mg）。遗传甲基丙二酸血症的四个cbl互补组的突变系，在体外具有正常数量的突变酶活性，其含有的CRM数量与对照系相当。另一方面，来自突变互补组的28个细胞系，在突变酶脱酶的结构基因位点表达突变，含有大量的CRM。来自mut亚组的7个品系，其剩余的突变酶活性反映了对辅助因子亲和力降低的结构改变的突变酶蛋白的存在，其检测到的CRM范围从对照的20%到100%不等。来自mut0组的21个细胞系，在体外没有检测到突变酶活性，在CRM方面分为两个群体：9个细胞系的可检测到CRM，范围从对照的3%到40%；另外12人没有检测到CRM（可检测的极限，小于对照组的1%）。这些结果强调了单一结构基因位点的大范围突变可能导致酶活性不足。
We developed a radioimmunoassay to quantitate material crossreacting immunochemically with human methylmalonyl-CoA mutase (methylmalonyl-CoA CoA-carbonylmutase, EC 5.4.99.2), and have applied this assay to extracts of fibroblasts from controls and from 32 patients with methylmalonic acidemia due to inherited deficiencies in mutase activity. Four control lines had an average of 237 ng of crossreacting material (CRM) per mg of cell protein (range, 193-297 ng/mg). Mutant lines from each of the four cbl complementation groups of inherited methylmalonic acidemia, which have normal amounts of mutase activity in vitro, contained quantities of CRM comparable to those of control lines. On the other hand, 28 cell lines from the mut complementation group, which express mutations at the structural gene locus for the mutase apoenzyme, contained widely diverse amounts of CRM. Each of seven lines from the mut- subgroup, whose residual mutase activity reflects the presence of a structurally altered mutase protein with reduced affinity for cofactor, had detectable CRM ranging from 20% to 100% of control. The 21 lines from the mut0 group, which have no detectable mutase activity in vitro, fell into two populations with regard to CRM: 9 lines had detectable CRM ranging from 3% to 40% of control; 12 others had no detectable CRM (limit of detectability, less than 1% of control). These results emphasize the wide range of mutations at a single structural gene locus that can result in deficient enzyme activity.