Intramolecular crosslinking of gamma-glutamyl transpeptidase.
Intramolecular crosslinking of gamma-glutamyl transpeptidase.
复制标题
γ-谷氨酰转肽酶的分子内交联。
DOI：
10.1016/0003-9861(87)90397-3
复制
发表时间：
1987
影响因子：
3.9
通讯作者：
Khadse,V
中科院分区：
文献类型：
--
作者：
Tate,SS;Khadse,V
γ-Glutamyl transpeptidase (rat kidney) is a heterodimeric glycoprotein (subunit molecular weights 52,000 and 25,000). In addition to its single-chain biosynthetic precursor (Mr78,000), glycosylated high molecular weight forms (Mr85,000–95,000) have been reported in various rat tissues as well as duringin vitrotranslation of its mRNA. Studies reported here suggest that these might be attributed to the anomalous behavior of intramolecularly crosslinked species. Thus, chemical crosslinking of the purified enzyme (as well as enzyme on the renal brush border membranes) by bifunctional reagents such as dimethyl suberimidate and by an active site-directed reagent, diazotizedp-aminohippurate, produces stable heterodimers which exhibit molecular weights identical to that of the native enzyme when subjected to gel filtration. However, when subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the crosslinked species exhibit apparentMrvalues of 85,000 to 110,000, depending upon the crosslinking agent used. Protein glycosylation alone does not account for such anomalous electrophoretic behavior; the extent and the regions of the enzyme involved in formation of crosslinks appear to exert considerable constraints upon their conformation even in denaturing media.
