TY - JOUR
T1 - Functional basis for the overlap in ligand interactions and substrate specificities of matrix metalloproteinases-9 and -2
AU - Xu, Xiaoping
AU - Chen, Zhihua
AU - Wang, Yao
AU - Yamada, Yoshishige
AU - Steffensen, Bjorn
PY - 2005/11/15
Y1 - 2005/11/15
N2 - The MMPs (matrix metalloproteinases) MMP-9 and -2 each possess a unique CBD (collagen-binding domain) containing three fibronectin type II-like modules. The present experiments investigated whether the contributions to ligand interactions and enzymatic activities by the CBD of MMP-9 (CBD-9) corresponded to those of CBD in MMP-2 (CBD-2). The interactions of recombinant CBD-9 with a series of collagen types and extracellular matrix molecules were characterized by protein-protein binding assays. CBD-9 bound native and denatured type I, II, III, IV and V collagen, as well as Matrigel and laminin, with apparent Kd values of (0.1-6.8) × 10-7 M, which were similar to the Kd values for CBD-2 [(0.2-3.7) × 10-7 M]. However, CBD-9 bound neither native nor denatured type VI collagen. We also generated two modified MMPs, MMP-9E402A and MMP-2E404A, by site-specific mutations in the active sites to obtain enzymes with intact ligand binding, but abrogated catalytic properties. In subsequent competitive binding assays, CBD-9 and MMP-9E402A inhibited the interactions of MMP-2E404A and, conversely, CBD-2 and MMP-2E404A competed with MMP-9 E402A binding to native and denatured type I collagens, pointing to shared binding sites. Importantly, the capacity of CBD-9 to disrupt the MMP-9 and MMP-2 binding of collagen translated to inhibition of the gelatinolytic activity of the enzymes. Collectively, these results emphasize the essential contribution of CBD-9 to MMP-9 substrate binding and gelatinolysis, and demonstrate that the CBDs of MMP-9 and MMP-2 bind the same or closely positioned sites on type I collagen.
AB - The MMPs (matrix metalloproteinases) MMP-9 and -2 each possess a unique CBD (collagen-binding domain) containing three fibronectin type II-like modules. The present experiments investigated whether the contributions to ligand interactions and enzymatic activities by the CBD of MMP-9 (CBD-9) corresponded to those of CBD in MMP-2 (CBD-2). The interactions of recombinant CBD-9 with a series of collagen types and extracellular matrix molecules were characterized by protein-protein binding assays. CBD-9 bound native and denatured type I, II, III, IV and V collagen, as well as Matrigel and laminin, with apparent Kd values of (0.1-6.8) × 10-7 M, which were similar to the Kd values for CBD-2 [(0.2-3.7) × 10-7 M]. However, CBD-9 bound neither native nor denatured type VI collagen. We also generated two modified MMPs, MMP-9E402A and MMP-2E404A, by site-specific mutations in the active sites to obtain enzymes with intact ligand binding, but abrogated catalytic properties. In subsequent competitive binding assays, CBD-9 and MMP-9E402A inhibited the interactions of MMP-2E404A and, conversely, CBD-2 and MMP-2E404A competed with MMP-9 E402A binding to native and denatured type I collagens, pointing to shared binding sites. Importantly, the capacity of CBD-9 to disrupt the MMP-9 and MMP-2 binding of collagen translated to inhibition of the gelatinolytic activity of the enzymes. Collectively, these results emphasize the essential contribution of CBD-9 to MMP-9 substrate binding and gelatinolysis, and demonstrate that the CBDs of MMP-9 and MMP-2 bind the same or closely positioned sites on type I collagen.
KW - Collagen
KW - Gelatinolysis
KW - Matrix metalloproteinase (MMP)
UR - http://www.scopus.com/inward/record.url?scp=28044435369&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=28044435369&partnerID=8YFLogxK
U2 - 10.1042/BJ20050650
DO - 10.1042/BJ20050650
M3 - Article
C2 - 16008524
AN - SCOPUS:28044435369
VL - 392
SP - 127
EP - 134
JO - Biochemical Journal
JF - Biochemical Journal
SN - 0264-6021
IS - 1
ER -