IK682, a tight binding inhibitor of TACE.
TNFalpha converting enzyme (TACE) is the major metalloproteinase for the processing of TNFalpha, a key inflammatory cytokine. IK682, a hydroxamate compound, was reported to be a potent and specific TACE inhibitor [J.J. Duan, L. Chen, Z.R. Wasserman, Z. Lu, R.Q. Liu, M.B. Covington, M. Qian, K.D. Hardman, R.L. Magolda, R.C. Newton, D.D. Christ, R.R. Wexler, C.P. Decicco, J. Med. Chem. 45 (2002) 4954-4957]. The binding kinetics of IK682 and the ectodomain of human TACE was examined. The k(on) of IK682 was determined as 1.1+/-0.3 x 10(8) M(-1) min(-1). No detectable dissociation of IK682 from TACE was observed following dialysis, dilution, and extensive washing over a maximum of 72 h. This was in contrast to the rapid dissociation of IK682 from ADAM10. LC/MS analysis of the TACE-IK682 complex after dissociation under denaturing conditions indicated that the tight binding is not due to covalent interaction. The X-ray crystal structure of TACE-IK682 complex revealed multiple binding points at the S1' and S3' sites and the movement of a loop (from Ala349 to Gly442) to accommodate the binding of the quinolinyl group of IK682 at the S3' pocket. The conformational changes of TACE may contribute significantly to the high affinity binding as a result of a more stable TACE-inhibitor complex.
Niu
Xiaoda
X
Department of Inflammation and Infection, Schering Plough Research Institute, 2015 Galloping Hill Road, Kenilworth, NJ 07033, USA. xioda.niu@spcorp.com
Umland
Shelby
S
Ingram
Richard
R
Beyer
Brian M
BM
Liu
Yan-Hui
YH
Sun
Jing
J
Lundell
Daniel
D
Orth
Peter
P
D051722:ADAM Proteins / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000378:metabolism; D000072198:ADAM17 Protein; D000409:Alanine / Q000737:chemistry / Q000378:metabolism; D001665:Binding Sites; D018360:Crystallography, X-Ray; D016207:Cytokines / Q000378:metabolism; D008401:Gas Chromatography-Mass Spectrometry; D005998:Glycine / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D006877:Hydroxamic Acids / Q000737:chemistry / Q000494:pharmacology*; D007700:Kinetics; D007769:Lactams / Q000737:chemistry / Q000494:pharmacology*; D008666:Metalloendopeptidases / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000378:metabolism; D011480:Protease Inhibitors / Q000737:chemistry / Q000494:pharmacology*
D016207:Cytokines; D006877:Hydroxamic Acids; C468787:IK 682; D007769:Lactams; D011480:Protease Inhibitors; D051722:ADAM Proteins; D008666:Metalloendopeptidases; D000072198:ADAM17 Protein; C000606462:ADAM17 protein, human; D000409:Alanine; D005998:Glycine