Assignments, secondary structure and dynamics of the inhibitor-free catalytic fragment of human fibroblast collagenase.

Autor: Moy, Franklin, Pisano, Michael, Chanda, Pranab, Urbano, Charlotte, Killar, Loran, Sung, Mei-Li, Powers, Robert
Zdroj: Journal of Biomolecular NMR; Jul1997, Vol. 10 Issue 1, p9-19, 11p
Abstrakt: Fibroblast collagenase (MMP-1), a 169-residue protein with amolecular mass of 18.7 kDa, is a matrix metalloproteinase which has beenassociated with pathologies such as arthritis and cancer. The assignments ofthe 1H, 15N, 13CO and13C resonances, determination of the secondary structure andanalysis of 15N relaxation data of the inhibitor-freecatalytic fragment of recombinant human fibroblast collagenase (MMP-1) arepresented. It is shown that MMP-1 is composed of a β-sheet consistingof five β-strands in a mixed parallel and antiparallel arrangement(residues 13–19, 48–53, 59–65, 82–85 and94–99) and three α-helices (residues 27–43, 112–124and 150–160). This is nearly identical to the secondary structuredetermined from the refined X-ray crystal structures of inhibited MMP-1. Themajor difference observed between the NMR solution structure ofinhibitor-free MMP-1 and the X-ray structures of inhibited MMP-1 is thedynamics of the active site. The 2D 15N-1H HSQCspectra, the lack of information in the 15N-edited NOESYspectra, and the generalized order parameters (S2) determinedfrom 15N T1, T2 and NOE datasuggest a slow conformational exchange for residues comprising the activesite (helix B, zinc ligated histidines and the nearby loop region) and ahigh mobility for residues Pro138-Gly144 in thevicinity of the active site for inhibitor-free collagenase. In contrast tothe X-ray structures, only the slow conformational exchange is lost in thepresence of an inhibitor. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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