Interaction of neutrophil elastase with hydrophobic polyanionic chelators

Abstract

The polyanionic calcium chelators, ethylenediamine-tetraacetic acid (EDTA), ethylene-bis-(oxyethylenenitrilo)-tetraacetic acid (EGTA), [bis-(O-aminophenoxy)-ethane-N,N,N',N'-tetraacetic acid (BAPTA), 1-[2-amino-5-(6-carboxyindol-2-yl) phenoxyl]-2-(2'-amino-5'-methylphenoxy)ethane-N,N,N1, N1-tetraacetic acid (INDO-1), 1-[2-(5-carboxyoxazol-2yl)-6-phenoxyl]-2-(2'-amino-5'- methylphenoxy)ethane-N,N,N',N'-tetraacetic acid (FURA-2), and 2-([2-bis-(carboxymethyl)-amino-5-methylphenoxy]-methyl(-6-methyl-8- bis-(bis-(carboxymethyl)-aminoquinoline (QUIN-2), are all inhibitors of amidolytic activity of human neutrophil elastase (HNE). With MeOSuc-Ala-Ala-Pro-Val-pNA as substrate, these chelators all display mixed partial competitive and partial noncompetitive inhibition, but with the smaller substrate, pGlu-Pro-Val-pNA, only the noncompetitive component persists. The most effective inhibitor is FURA-2, with an apparent Ki of 0.5-0.7 mM. QUIN-2 is somewhat less effective, with a Ki of 2 mM, while EDTA is much less effective, with a Ki of 7 mM. In general, the more hydrophobic chelators are the best inhibitors, although INDO-1, which is about the same size as FURA-2, is surprisingly ineffective as an inhibitor. The chelators no longer function as effective inhibitors if their carboxyl groups are blocked by esterification with acetoxymethyl groups or by complexation with calcium ions, indicating that their binding to HNE is mediated in part through electrostatic interactions with a center of positive charge on the protein.(ABSTRACT TRUNCATED AT 250 WORDS)

Structural and functional comparison of native pentameric, denatured monomeric and biotinylated C‐reactive protein

“…We have shown here that the serine proteases PMSF and AEBSF and the neutrophil‐specific elastase II inhibitor inhibited the cleavage of mCRP, strongly suggesting that the enzyme responsible is elastase. EDTA also prevented the degradation of mCRP by neutrophil‐derived enzymes, which is consistent with the observation that elastase requires calcium to function 33 . Shepard et al .…”

“…EDTA also prevented the degradation of mCRP by neutrophil-derived enzymes, which is consistent with the observation that elastase requires calcium to function. 33 Shepard et al showed that neutrophil-derived enzymatic cleavage of CRP resulted in fragments with biological activities; however, commonly a 30-fold molar excess over nCRP was required to induce cell activation. 34,35 Considering that only mCRP is susceptible to enzymatic degradation, it is questionable if in vivo sufficient levels of peptides could be generated to have any biological effect.…”

Ultraviolet radiation and skin aging: roles of reactive oxygen species, inflammation and protease activation, and strategies for prevention of inflammation‐induced matrix degradation – a review

“…Other non-specific inhibitors of HLE are fatty acids, bile acids, and pyrene trisulfonic acid (Table IV) [121][122][123][124]. These compounds are all reversible inhibitors, and form no covalent interactions with the enzyme.…”

Anionic- and Lipophilic-Mediated Surface Binding Inhibitors of Human Leukocyte Elastase

“…HLE inactivation through active site acylation has been accomplished by β-lactams, isoxazolines, saccharins, and benzisothiazolones . Also reported as inhibitors of HLE are the chemical classes of phenylbutyrates, oligonucleotides, polyanionic chelators, heparin derivatives, peptidyl carbamates, sulfonamidobenzoylglycines, isocoumarins, and biphenyldisulfonic acid copolymer …”