Influence of some natural and semisynthetic agents on elastase and cathepsin G from polymorphonuclear granulocytes

The in vitro effect of eglin C, glycosaminoglycan-peptide complex "DAK 16", glycosaminoglycan polysulfate and sodium pentosan polysulfate on the PMN-enzymes elastase and cathepsin G was investigated. The activity of elastase and cathepsin G was measured with the highly specific chromogenic substrates methoxysuccinyl-l-ala-l-ala-l-pro-l-val-p-nitroaniline and succinyl-l-ala-l-ala-l-pro-l-phenyl-alanin-p-nitroaniline. Eglin C and DAK 16 displayed a pronounced inhibition of PMN-elastase and PMN-cathepsin G. Surprisingly a higher amount of product in the elastase containing assays were found in the presence of glycosaminoglycan polysulfate and sodium pentosan polysulfate. The higher cleavage of the elastase substrate is related back to an electrostatic interaction of the polysulfates with this substrate. Both polysulfates strongly inhibited cathepsin G. The qualitatively and quantitatively different behavior of the drugs on elastase and cathepsin G are discussed with regard to their in vivo contribution to the therapy of chronic inflammatory joint diseases.