Lack of effect of carbohydrate depletion on some properties of human mast cell chymase
| Autor: | Mizuo Miyazaki, Kazumasa Takao, Naotaka Shiota, Shinji Takai, Takafumi Ishihara, Keifu Song, Kazuo Nishimura |
|---|---|
| Rok vydání: | 1999 |
| Předmět: |
Glycosylation
Hot Temperature Size-exclusion chromatography Carbohydrates Biophysics Biochemistry Substrate Specificity chemistry.chemical_compound Chymases Polysaccharides Enzyme Stability Renin–angiotensin system Humans Mast Cells Enzyme kinetics Molecular Biology chemistry.chemical_classification Chemistry Serine Endopeptidases Chymase Hydrogen-Ion Concentration Carbohydrate Angiotensin II Kinetics Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase Enzyme |
| Zdroj: | Biochimica et Biophysica Acta (BBA) - General Subjects. 1427:74-81 |
| ISSN: | 0304-4165 |
| Popis: | Human chymase from vascular tissues was purified to homogeneity by heparin affinity and gel filtration chromatography. Treatment of human chymase with endoglycosidase F resulted in cleavage of the carbohydrate moiety yielding a deglycosylation product that did not lose its catalytic activity. This enzymatic deglycosylation product was enough to explore possibilities that N-glycan might modify some properties of human chymase. Substrate specificity, optimum pH and the elution profile from the heparin affinity gel were not affected by the deglycosylation. Only a slight but significant difference was observed in the Km value for conversion of angiotensin I to angiotensin II. Other kinetic constants such as kcat were not influenced. The kinetics of conversion of big endothelin-1 to endothelin-1(1-31) were not significantly affected. The deglycosylated human chymase was more susceptible to deactivation under alkaline pH and thermal stress. Even at physiological temperature and pH, the activity of glycosylated human chymase was more stable. From these results, it appears that the N-glycan of human chymase contributes to the stability of this enzyme but not to its functional properties. |
| Databáze: | OpenAIRE |
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