M. Tortorella et al., The thrombospondin motif of aggrecanase-1 (ADAMTS-4) is critical for aggrecan substrate recognition and cleavage, J BIOL CHEM, 275(33), 2000, pp. 25791-25797
Aggrecanase-1 (ADAMTS-4) is a member of the a disintegrin and metalloprotea
se with thrombospondin motifs (ADAMTS) protein family that was recently ide
ntified. Aggrecanase-1 is one of two ADAMTS cartilage-degrading enzymes pur
ified from interleukin-1-stimulated bovine nasal cartilage (Tortorella, M.
D., Burn, T. C., Pratta, M. A., Abbaszade, I., Hollis, J. Ri., Liu, R., Ros
enfeld, S. A,, Copeland, R. A., Decicco, C. P., Wynn, R., Rockwell, A, Yang
, F., Duke, J. L., Solomon, K., George, R, Bruckner, R., Nagase, H., Itoh,
Y., Ellis, D. M., Boss, H., Wiswall, B. H., Murphy, K., Hillman, M. C., Jr.
, Hollis, G. F., and Arner, E.C. (1999) Science 284, 1664-1666; 2 Abbaszade
, I., Liu, R. Q., Yang, F., Rosenfeld, S. A., Boss, O. H., Link, J. R., Ell
is, D. M., Tortorella, M. D., Pratta, M. A., Hollis, J. M., Wynn, R., Duke,
J. L., George, H. J., Hillman, M. C., Jr., Murphy, K., Wiswall, B. H., Cop
eland, R. A., Decicco, C. P., Bruckner, R., Nagase, H., Itoh, Y., Newton, R
. C., Magolda, R. L., Trzaskos, J. M., and Burn, T. C. (1999) J. Biol. Chem
. 274, 23443-23450). The aggrecan products generated by this enzyme are fou
nd in cartilage cultures stimulated with cytokines and in synovial fluid fr
om patients with arthritis, suggesting that aggrecanase-1 may be important
in diseases involving cartilage destruction. Here we demonstrate that the t
hrombospondin type-1 (TSP-1) motif located within the C terminus of aggreca
nase-1 binds to the glycosaminoglycans of aggrecan. Data from several studi
es indicate that this binding of aggrecanase-1 to aggrecan through the TSP-
1 motif is necessary for enzymatic cleavage of aggrecan. 1) A truncated for
m of aggrecanase-1 lacking the TSP-I motif was not effective in cleaving ag
grecan. 2) Several peptides representing different regions of the TSP-1 mot
if effectively blocked aggrecanase-1 cleavage of aggrecan by preventing the
enzyme from binding to the substrate. 3) Aggrecanase-1 was not effective i
n cleaving glycosaminoglycan-free aggrecan. Taken together, these data sugg
est that the TSP-1 motif of aggrecanase-1 is critical for substrate recogni
tion and cleavage.