title: Structural determinants of the ADAM inhibition by TIMP-3: crystal structure of the TACE-N-TIMP-3 complex.
abstract: TIMP-3 (tissue inhibitor of metalloproteinases 3) is unique among the TIMP inhibitors, in that it effectively inhibits the TNF-alpha converting enzyme (TACE). In order to understand this selective capability of inhibition, we crystallized the complex formed by the catalytic domain of recombinant human TACE and the N-terminal domain of TIMP-3 (N-TIMP-3), and determined its molecular structure with X-ray data to 2.3 A resolution. The structure reveals that TIMP-3 exhibits a fold similar to those of TIMP-1 and TIMP-2, and interacts through its functional binding edge, which consists of the N-terminal segment and other loops, with the active-site cleft of TACE in a manner similar to that of matrix metalloproteinases (MMPs). Therefore, the mechanism of TIMP-3 binding toward TACE is not fundamentally different from that previously elucidated for the MMPs. The Phe34 phenyl side chain situated at the tip of the relatively short sA-sB loop of TIMP-3 extends into a unique hydrophobic groove of the TACE surface, and two Leu residues in the adjacent sC-connector and sE-sF loops are tightly packed in the interface allowing favourable interactions, in agreement with predictions obtained by systematic mutations by Gillian Murphy's group. The combination of favourable functional epitopes together with a considerable flexibility renders TIMP-3 an efficient TACE inhibitor. This structure might provide means to design more efficient TIMP inhibitors of TACE.
authors.affiliation: Max-Planck-Institut für Biochemie, Proteinase Research Group, Am Klopferspitz 18, D-82152 Martinsried, Germany.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Wisniewska
authors.forename: Peter
authors.initials: P
authors.lastname: Goettig
authors.forename: Klaus
authors.initials: K
authors.lastname: Maskos
authors.forename: Edward
authors.initials: E
authors.lastname: Belouski
authors.forename: Dwight
authors.initials: D
authors.lastname: Winters
authors.forename: Randy
authors.initials: R
authors.lastname: Hecht
authors.forename: Roy
authors.initials: R
authors.lastname: Black
authors.forename: Wolfram
authors.initials: W
authors.lastname: Bode
mesh_terms: D051722:ADAM Proteins / Q000037:antagonists & inhibitors* / Q000737:chemistry*; D000072198:ADAM17 Protein; D000595:Amino Acid Sequence; D018360:Crystallography, X-Ray; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011485:Protein Binding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D019717:Tissue Inhibitor of Metalloproteinase-3 / Q000737:chemistry* / Q000378:metabolism*
chemical_list: C088390:TIMP3 protein, human; D019717:Tissue Inhibitor of Metalloproteinase-3; D051722:ADAM Proteins; D000072198:ADAM17 Protein; C000606462:ADAM17 protein, human