Jurkat T cells express a functional neutral endopeptidase activity (CALLA) involved in T cell activation.

摘要: We have characterized a T lymphocyte endopeptidase activity that hydrolyses succinyl-alanine-alanine-phenylalanine-paranitroanilide (Suc-Ala-Ala-Phe-pNa). Hydrolysis of this substrate by intact Jurkat cells was markedly enhanced when exogenous aminopeptidase N added to the incubation medium. It thus appears release paranitroaniline from Suc-Ala-Ala-Phe-pNA results combination two distinct enzymatic activities: (i) an cleaves at alanyl bond and (ii) ultimately phenylalanyl bond. This cleavage further confirmed HPLC analysis. Specific 24.11 inhibitors were shown inhibit activity. These features are reminiscent characteristics neutral (NEP, also known as 24.11, CALLA or CD10). Anti-CD10 monoclonal antibodies (mAbs) recognized CD10+ B cell line Raji, but not assessed FACS is probably due lack sensitivity method, level NEP in being 3-5% measured lines. mAbs immunoprecipitated activities both Raji cells, demonstrating lymphocytes express CALLA-related endopeptidase. demonstrate endopeptidases same molecular weight, less functional mRNA than there least shorter transcripts (1.8 0.8 kb) cells.(ABSTRACT TRUNCATED AT 250 WORDS)