Download MendeleyExpression, characterization and structure determination of an active site mutant (Glu202-Gln) of mini-stromelysin-1.
Steele, D.L., El-Kabbani, O., Dunten, P., Windsor, L.J., Kammlott, R.U., Crowther, R.L., Michoud, C., Engler, J.A., Birktoft, J.J.(2000) Protein Eng 13: 397-405
- PubMed: 10877850
- DOI: https://doi.org/10.1093/protein/13.6.397
- Primary Citation of Related Structures:
1C3I, 1C8T - PubMed Abstract:
Human stromelysin-1 is a member of the matrix metalloproteinase (MMP) family of enzymes. The active site glutamic acid of the MMPs is conserved throughout the family and plays a pivotal role in the catalytic mechanism. The structural and functional consequences of a glutamate to glutamine substitution in the active site of stromelysin-1 were investigated in this study. In contrast to the wild-type enzyme, the glutamine-substituted mutant was not active in a zymogram assay where gelatin was the substrate, was not activated by organomercurials and showed no activity against a peptide substrate. The glutamine-substituted mutant did, however, bind to TIMP-1, the tissue inhibitor of metalloproteinases, after cleavage of the propeptide with trypsin. A second construct containing the glutamine substitution but lacking the propeptide was also inactive in the proteolysis assays and capable of TIMP-1 binding. X-ray structures of the wild-type and mutant proteins complexed with the propeptide-based inhibitor Ro-26-2812 were solved and in both structures the inhibitor binds in an orientation the reverse of that of the propeptide in the pro-form of the enzyme. The inhibitor makes no specific interactions with the active site glutamate and a comparison of the wild-type and mutant structures revealed no major structural changes resulting from the glutamate to glutamine substitution.
Organizational Affiliation:
Department of Biochemistry and Molecular Genetics, Oral Cancer Research Center and Research Center in Oral Biology, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
