Drosophila TIMP is a potent inhibitor of MMPs and TACE: similarities in structure and function to TIMP-3.
The four tissue inhibitors of metalloproteinases (TIMPs) are endogenous inhibitors that regulate the activity of matrix metalloproteinases (MMPs) and certain disintegrin and metalloproteinase (ADAM) family proteases in mammals. The protease inhibitory activity is present in the N-terminal domains of TIMPs (N-TIMPs). In this work, the N-terminal inhibitory domain of the only TIMP produced by Drosophila (dN-TIMP) was expressed in Escherichia coli and folded in vitro. The purified recombinant protein is a potent inhibitor of human MMPs, including membrane-type 1-MMP, although it lacks a disulfide bond that is conserved in all other known N-TIMPs. Titration with the catalytic domain of human MMP-3 [MMP-3(DeltaC)] showed that dN-TIMP prepared by this method is correctly folded and fully active. dN-TIMP also inhibits, in vitro, the activity of the only two MMPs of Drosophila, dm1- and dm2-MMPs, indicating that the Drosophila TIMP is an endogenous inhibitor of the Drosophila MMPs. dN-TIMP resembles mammalian N-TIMP-3 in strongly inhibiting human tumor necrosis factor-alpha-converting enzyme (TACE/ADAM17) but is a weak inhibitor of human ADAM10. Models of the structures of dN-TIMP and N-TIMP-3 are strikingly similar in surface charge distribution, which may explain their functional similarity. Although the gene duplication events that led to the evolutionary development of the four mammalian TIMPs might be expected to be associated with functional specialization, Timp-3 appears to have conserved most of the functions of the ancestral TIMP gene.
Department of Biomedical Sciences, Florida Atlantic University, Boca Raton, Florida 33431, USA.
Shuo
S
Wei
Zhihong
Z
Xie
Elena
E
Filenova
Keith
K
Brew
D051722:ADAM Proteins; D000072198:ADAM17 Protein; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D017931:DNA Primers; D004330:Drosophila; D004591:Electrophoresis, Polyacrylamide Gel; D061965:Matrix Metalloproteinase Inhibitors; D008666:Metalloendopeptidases / Q000037:antagonists & inhibitors*; D008969:Molecular Sequence Data; D017510:Protein Folding; D013056:Spectrophotometry, Ultraviolet; D013329:Structure-Activity Relationship; D019714:Tissue Inhibitor of Metalloproteinases / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*
D017931:DNA Primers; D061965:Matrix Metalloproteinase Inhibitors; D019714:Tissue Inhibitor of Metalloproteinases; D051722:ADAM Proteins; D008666:Metalloendopeptidases; D000072198:ADAM17 Protein; C000606462:ADAM17 protein, human