Molecular cloning of matrix Gla protein: implications for substrate recognition by the vitamin K-dependent gamma-carboxylase.

Matrix Gla protein (MGP), a low molecular weight protein found in bone, dentin, and cartilage, contains 5 residues of the vitamin K-dependent amino acid gamma-carboxyglutamic acid (Gla). We have used antibodies raised against MGP and oligonucleotide probes to screen a lambda gt11 cDNA library constructed from the rat osteosarcoma cells (line ROS 17/2) that had been pretreated with 1 alpha,25-dihydroxyvitamin D3. By sequencing several cloned cDNAs, we established a 523-base-pair sequence that predicts an 84-residue mature MGP and a 19-residue hydrophobic signal peptide.

Kinetic studies on the interaction of eglin c with human leukocyte elastase and cathepsin G.

We have investigated the inhibition of human leukocyte elastase and cathepsin G by recombinant Eglin c under near physiological conditions. The association rate constants k on of Eglin c for elastase and cathepsin G were 1.3 X 10(7) M-1 s-1 and 2 X 10(6) M-1 s-1, respectively.

Stimulated release of neutral proteinases elastase and cathepsin G from inflammatory rat polymorphonuclear leukocytes.

Rat leukocytes from inflammatory peritoneal exudates respond in vitro to a variety of chemotactic and phagocytic stimuli by releasing both elastase and cathepsin G neutral proteinase enzyme activities. PAF, FMLP, and PMA stimulated a rapid, cytochalasin B-dependent, dose-related release of both enzymes; however, leukotriene B4 was inactive. It was not possible to measure the activity of zymosan-activated serum on these cells as rat serum contains high levels of proteinase inhibitors.