HUMAN JEJUNAL TRANSGLUTAMINASE - DEMONSTRATION OF ACTIVITY, ENZYME-KINETICS AND SUBSTRATE-SPECIFICITY WITH SPECIAL RELATION TO GLIADIN AND CELIAC-DISEASE
HUMAN JEJUNAL TRANSGLUTAMINASE - DEMONSTRATION OF ACTIVITY, ENZYME-KINETICS AND SUBSTRATE-SPECIFICITY WITH SPECIAL RELATION TO GLIADIN AND CELIAC-DISEASE
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DOI：
10.1042/cs0680573
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发表时间：
1985-01-01
期刊：
影响因子：
6
通讯作者：
PETERS, TJ
中科院分区：
文献类型：
--
作者：
BRUCE, SE;BJARNASON, I;PETERS, TJ
首次用放射测定法测定了人空肠粘膜中谷氨酰胺转氨酶的活性。该酶的活性与其他组织相似，最适pH为9.0，对钙离子的绝对需要量和腐胺的表观Km分别为0.15 mmol/L。以多种饲料蛋白为受体的空肠谷氨酰胺转氨酶活性测定表明，醇溶蛋白具有较高的活性，与标准底物二甲基酪蛋白相当。醇溶蛋白的脱酰胺化显著降低了其受体活性。胶原、卵清蛋白、弹性蛋白和玉米醇溶蛋白的受体活性很低。与炎症性肠病相比，4例未经治疗的乳糜泻患者的空肠活检组织中谷氨酰胺转氨酶活性升高。8例乳糜泻缓解期患者，刷状缘α-葡萄糖苷酶水平正常，与对照组相比，转谷氨酰胺酶活性升高。肠道谷氨酰胺转氨酶活性可能在醇溶蛋白与组织结合中起重要作用，从而在乳糜泻的发病机制中起重要作用。
Transglutaminase activity was demonstrated by radiometric assay for the 1st time in human jejunal mucosa. The activity was similar to that in other tissues, with a pH optimum of 9.0, an absolute requirement for Ca2+ and an apparent Km for putrescine of 0.15 mmol/l. Assay of jejunal transglutaminase activity with a variety of dietary proteins as acceptors showed high activity with gliadin, comparable with that of the standard substrate, dimethylcasein. Deamidation of the gliadin markedly reduced its acceptor activity. Collagen, ovalbumin, elastin and zein exhibited very low acceptor activities. Increased transglutaminase activity was demonstrated in jejunal biopsies from 4 patients with untreated celiac disease compared with inflammatory bowel disease. Eight patients with celiac disease in remission, with normal levels of brush border .alpha.-glucosidase, showed elevated transglutaminase activities compared with those of controls. Intestinal transglutaminase activity may be important in gliadin binding to tissues and thus in the pathogenesis of celiac disease.