Specificity of inhibition of matrix metalloproteinase activity by doxycycline: relationship to structure of the enzyme

Arthritis Rheum. 1999 Jun;42(6):1140-6. doi: 10.1002/1529-0131(199906)42:6<1140::AID-ANR10>3.0.CO;2-7.


Objective: To investigate the inhibition of matrix metalloproteinase 1 (MMP-1), MMP-8, and MMP-13 by doxycycline, and to determine whether the variable hemopexin-like domain of each MMP was responsible for the differences in susceptibility to doxycycline inhibition among these collagenases.

Methods: Recombinant human MMP-1 (collagenase 1), MMP-8 (collagenase 2), and MMP-13 (collagenase 3), truncated forms of MMP-8 and MMP-13 lacking the hemopexin-like domain, and a mutant form of truncated MMP-13 were used in these studies. The activity of the full-length MMP in the presence of doxycycline was tested against type II collagen, a natural substrate for the enzymes. A small peptolide substrate was used to determine which structural features of the MMPs were related to sensitivity to doxycycline inhibition.

Results: The activity of MMP-13 and MMP-8 against type II collagen was inhibited by 50-60% by 30 microM doxycycline, while that of MMP-1 was inhibited only 18% by 50 microM doxycycline. In contrast, in experiments with the peptolide substrate, neither full-length nor truncated MMP-13 was inhibited until the concentration of the drug exceeded 90 microM. MMP-8 and truncated MMP-8 were sensitive to inhibition by 30 microM doxycycline, while MMP-1 was slightly inhibited (14%) by 90 microM doxycycline. For MMP-8, inhibition was reversible upon dilution and was independent of the order in which the reagents were added. Kinetic analysis of the inhibition constant (K(i)) of MMP-8 (K(i) = 36 microM) and truncated MMP-8 (K(i) = 77 microM) indicated that inhibition was noncompetitive.

Conclusion: Significant inhibition of MMP-13 and MMP-8 activity against collagen occurred in vitro at concentrations that were near the concentrations achieved in serum after oral dosing. Studies with truncated enzymes and 2 substrates suggest that doxycycline disrupts the conformation of the hemopexin-like domain of MMP-13 and the catalytic domain of MMP-8.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Anti-Bacterial Agents / pharmacology*
  • Collagen / drug effects
  • Doxycycline / pharmacology*
  • Humans
  • Matrix Metalloproteinase 1
  • Matrix Metalloproteinase 13
  • Matrix Metalloproteinase 8
  • Matrix Metalloproteinase Inhibitors*
  • Molecular Sequence Data
  • Recombinant Proteins / antagonists & inhibitors
  • Structure-Activity Relationship
  • Substrate Specificity


  • Anti-Bacterial Agents
  • Matrix Metalloproteinase Inhibitors
  • Recombinant Proteins
  • Collagen
  • MMP13 protein, human
  • Matrix Metalloproteinase 13
  • Matrix Metalloproteinase 8
  • Matrix Metalloproteinase 1
  • Doxycycline