Pelzer C F, Norum R A
Am J Hum Genet. 1985 Jan;37(1):147-52.
Isoenzymes of human red cell glutamate-pyruvate transaminase (GPT) were resolved by isoelectric focusing (IEF) of hemolysates in polyacrylamide gels at pH 5.0-7.0. The bands of enzyme activity required both alpha-ketoglutarate and L-alanine in the staining mixture for visualization, indicating that the bands were not lactate dehydrogenase or glutamate dehydrogenase. Phenotyping of 41 individuals by IEF, including types GPT 1, 2A, 1-2A, 1-2B, and 2A-2B, agreed with the typing results obtained by electrophoresis in starch gels and in polyacrylamide gels at acid and alkaline pH. Analysis of one kindred demonstrated autosomal codominant transmission of the rare GPT*2B gene through 3 generations. IEF facilitates phenotyping by permitting identification of the GPT types on a single gel with a considerable reduction in time and cost. Although no new variants were found in this investigation, IEF may be more powerful for the recognition of presently undetected variants of GPT.
通过在pH 5.0 - 7.0的聚丙烯酰胺凝胶中对溶血产物进行等电聚焦（IEF），分离出了人红细胞谷丙转氨酶（GPT）的同工酶。酶活性条带在染色混合物中需要α-酮戊二酸和L-丙氨酸才能显色，这表明这些条带不是乳酸脱氢酶或谷氨酸脱氢酶。通过IEF对41个人进行表型分析，包括GPT 1、2A、1 - 2A、1 - 2B和2A - 2B型，结果与在淀粉凝胶以及酸性和碱性pH条件下的聚丙烯酰胺凝胶中进行电泳所获得的分型结果一致。对一个家系的分析表明，罕见的GPT*2B基因以常染色体共显性方式传递了3代。IEF通过允许在单一凝胶上鉴定GPT类型，极大地减少了时间和成本，从而便于进行表型分析。尽管在本次研究中未发现新的变异体，但IEF对于识别目前未检测到的GPT变异体可能更具效力。
