Navegando por Palavras-chave "angiostatin"

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    Cathepsin V, but not cathepsins L, B and K, may release angiostatin-like fragments from plasminogen
    (Walter de Gruyter & Co, 2008-02-01) Puzer, Luciano; Barros, Nilana M. T. [UNIFESP]; Paschoalin, Thaysa [UNIFESP]; Hirata, Izaura Y. [UNIFESP]; Tanaka, Aparecida S. [UNIFESP]; Oliveira, Marcelo C.; Broemme, Dieter; Carmona, Adriana K. [UNIFESP]; Univ British Columbia; Universidade Federal de São Carlos (UFSCar); Universidade Federal de São Paulo (UNIFESP); Universidade de São Paulo (USP)
    Cathepsin V is a lysosomal cysteine peptidase highly expressed in corneal epithelium; however, its function in the eye is still unknown. Here, we describe the capability of cathepsin V to hydrolyze plasminogen, which is also expressed in human cornea at levels high enough to produce physiologically relevant amounts of angiostatin-related molecules. the co-localization of these two proteins suggests an important role for the enzyme in the maintenance of corneal avascularity, essential for optimal visual performance. Sodium dodecyl sulfate-polyacrylamide gel electrophoretic analysis of plasminogen digestion by cathepsin V revealed the generation of three major products of 60, 50 and 40 kDa, which were electrotransferred to polyvinylidene difluoride membranes and excised for characterization. NH2-terminal amino acid sequencing of these fragments revealed the sequences EKKVYL, TEQLAP and LLPNVE, respectively. These data are compatible with cleavage sites at plasminogen F94-E95, S358-T359 and V468-L469 peptide bonds generating fragments of the five-kringle domains. in contrast, we did not detect any plasminogen degradation by cathepsins B, K and L. Using a Matrigel assay, we confirmed the angiogenesis inhibition activity on endothelial cells caused by plasminogen processing by cathepsin V. Our results suggest a novel physiological role for cathepsin V related to the control of neovascularization in cornea.
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    Plasminogen hydrolysis by cathepsin S and identification of derived peptides as selective substrate for cathepsin V and cathepsin L inhibitor
    (Walter de Gruyter Gmbh, 2010-05-01) Coppini, Larissa Pereira [UNIFESP]; Barros, Nilana M. T. [UNIFESP]; Oliveira, Marcela [UNIFESP]; Hirata, Izaura Y. [UNIFESP]; Alves, Marcio F. M. [UNIFESP]; Paschoalin, Thaysa [UNIFESP]; Assis, Diego M. [UNIFESP]; Juliano, Maria A. [UNIFESP]; Puzer, Luciano; Broemme, Dieter; Carmona, Adriana K. [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Univ Fed Triangulo Mineiro; Univ British Columbia
    Plasminogen is a glycoprotein implicated in angiogenesis and fibrin clot degradation associated with the release of angiostatin and plasmin activation, respectively We have recently reported that cathepsin V. but not cathepsins L. B, and K. can release angiostatin-like fragments from plasminogen. Here, we extended the investigation to cathepsin S which has been implicated in angiogenesis and tumor cell proliferation. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of plasminogen hydrolysis by cathepsin S revealed generation of two fragments (60 and 38 kDa). Amino-terminal sequencing indicated that cleavage occurs at the Leu469-Leu470 peptide bond. in contrast to cathepsin V, which possesses antiangiogenic activity, cathepsin S plasminogen cleavage products were not capable of inhibiting angiogenesis on endothelial cells. Moreover, we explored the different selectivities presented by cathepsins V and S towards plasminogen and synthesized fluorescence resonance energy transfer peptides encompassing the hydrolyzed peptide bonds by both enzymes. the peptide Abz-VLFEKKQ-EDDnp (Abz=ortho-aminobenzoic acid; EDDnp=N-[2,4-dinitrophenyl]ethylenediamine), hydrolyzed by cathepsin V at the Phe-Glu bond. is a selective substrate for the enzyme when compared with cathepsins B. L, and S, whereas Abz-VLFEKKVYLQ-EDDnp is an efficient cathepsin L inhibitor. the demonstrated importance of the S-3'-P-3' interaction indicates the significance of the extended subsites for enzyme specificity and affinity.