title: Matrix metalloproteinase-9 activity detected in body fluids is the result of two different enzyme forms.
abstract: In vitro activation of matrix metalloproteinase-9 (MMP-9) (Gelatinase B) with MMP-3 shows the presence of two different forms: an 82 kDa, N-terminal truncated form, and a 65 kDa, N- and C-terminal truncated form. So far the presence of the 65 kDa form has not been reported in vivo. Affinity chromatography was performed to separate MMP-9 from MMP-2 and immunoprecipitation to isolate ∼65 kDa MMP-9 from 82 kDa MMP-9 in sera of healthy donors. The presence of ∼65 kDa active MMP-9 was demonstrated both with gelatin zymography and western blot analysis. The ∼65 kDa MMP-9 lacks the haemopexin domain required for the high-affinity binding of the tissue inhibitor TIMP-1, and can be evaluated by activity assay in the presence of TIMP-1. This opens the possibility to investigate the role of this form of MMP-9 that escapes physiological regulation.
authors.affiliation: Section of Biochemistry and Clinical Biochemistry, Department of Biochemistry and Molecular Biology, University of Ferrara, Via Luigi Borsari 46, Italy.
authors.forename: Tiziana
authors.initials: T
authors.lastname: Bellini
authors.forename: Alessandro
authors.initials: A
authors.lastname: Trentini
authors.forename: Maria C
authors.initials: MC
authors.lastname: Manfrinato
authors.forename: Carmine
authors.initials: C
authors.lastname: Tamborino
authors.forename: Carlo Alberto
authors.initials: CA
authors.lastname: Volta
authors.forename: Valentina
authors.initials: V
authors.lastname: Di Foggia
authors.forename: Enrico
authors.initials: E
authors.lastname: Fainardi
authors.forename: Franco
authors.initials: F
authors.lastname: Dallocchio
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Castellazzi
mesh_terms: D000328:Adult; D001826:Body Fluids / Q000201:enzymology*; D005260:Female; D006801:Humans; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000097:blood / Q000378:metabolism; D019278:Matrix Metalloproteinase 3 / Q000097:blood / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000097:blood / Q000737:chemistry* / Q000378:metabolism*; D061965:Matrix Metalloproteinase Inhibitors / Q000378:metabolism / Q000494:pharmacology; D012016:Reference Values; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000378:metabolism
chemical_list: D061965:Matrix Metalloproteinase Inhibitors; D019715:Tissue Inhibitor of Metalloproteinase-1; D019278:Matrix Metalloproteinase 3; C522361:MMP2 protein, human; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9