| Summary: | 碩士 === 台北醫學院 === 醫學研究所 === 85 === AbstractTransglutaminases (TGase) are a family of calcium-
dependent enzyme catalyzing an acyltransfer reaction between
peptide bound glutamine and lysine residues or primary amine. A
novel calcium-independent TGase-like enzyme has been
demonstrated recently in mouse intestinal mucosal cells. To
purify this novel enzyme, saturated ammonium sulfate was used to
fractionate the cytosol preparations. The majority of calcium-
independent TGase activities was detected in the fraction
precipitated at 45%~55% saturated ammonThermal stability of this
novel enzyme was studied at 37(C and 50(C. The calcium-
independent TGase is more stable than calcium-dependent
transglutaminase at 37(C. However, activities of both enzyme
were abolished at 50(C. When protease inhibitors ( PMSF,
Pepstatin, Leupeptin ) were included in the homogenizing buffer,
the enzyme activity was decreased as compared to that prepared
in the abscense of protease inhibitors.The effect of stress and
tissue repair on rat intestinal mucosal transglutaminase was
studied by immunohistochemical method. The intensity of stress
of transglutaminase-immunostaining increased in the intestinal
mucosal tissue with the duration. To investigate whether stress
causes apoptosis in duodenal mucosal villus. DNA fragmentation
induced by apaptosis was assessed by in situ detection. The
phenomenon of apoptotic DNA fragmentation was observed in the
intestinal mucosal villi. It is suggested that the
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