摘要
The defect of TPP Ⅰ causes a disease, late infantile neuronal ceroid lipofuscinosis（LINCL, CLN2）. To investigate the bio-activity of tripeptidyl peptidase Ⅰ （TPP Ⅰ ） from rat kidneys, the effects of digestion of angiotensin Ⅱ （Ang Ⅱ ） and a synthetic endo-type substrate（ Gly^1-Lys-Pro^5-lie-Pro^5-Phe-Phe-Arg-Leu-Lys^10） via TPP I were ana- lyzed by HPLC and TOF-MS. The data suggest that the degradation rate of Ang I1 can reach 18. 2% by the rat TPP I and DRV（Asp-Arg-Val） can be released from N-termini of Ang Ⅱ within 16 h. In addition, the synthetic endotype substrate is cleaved at the same position between Phe6 and Phe^7. Accordingly, TPP Ⅰ shows two kinds of peptidase activities. One is a tripeptidyl peptidase activity and the other is a pepstatin insensitive carboxyl endopeptidase activity. Tripeptidyl peptidase activity and pepstatin insensitive carboxyl endopeptidase activity seem to be dual phases of one enzyme, TPP Ⅰ.
The defect of TPP Ⅰ causes a disease, late infantile neuronal ceroid lipofuscinosis（LINCL, CLN2）. To investigate the bio-activity of tripeptidyl peptidase Ⅰ （TPP Ⅰ ） from rat kidneys, the effects of digestion of angiotensin Ⅱ （Ang Ⅱ ） and a synthetic endo-type substrate（ Gly^1-Lys-Pro^5-lie-Pro^5-Phe-Phe-Arg-Leu-Lys^10） via TPP I were ana- lyzed by HPLC and TOF-MS. The data suggest that the degradation rate of Ang I1 can reach 18. 2% by the rat TPP I and DRV（Asp-Arg-Val） can be released from N-termini of Ang Ⅱ within 16 h. In addition, the synthetic endotype substrate is cleaved at the same position between Phe6 and Phe^7. Accordingly, TPP Ⅰ shows two kinds of peptidase activities. One is a tripeptidyl peptidase activity and the other is a pepstatin insensitive carboxyl endopeptidase activity. Tripeptidyl peptidase activity and pepstatin insensitive carboxyl endopeptidase activity seem to be dual phases of one enzyme, TPP Ⅰ.
基金
SupportedbytheScientificResearchFundfortheReturnedOverseasChineseScholars,StateEducationMinistry.
