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Inhibition of human leukocyte elastase and cathepsin G by extended peptides and subunits derived from human C-reactive protein

“…Side chain protecting groups were: tert-butyloxycarbonyl (t-Boc) for Lys and Trp; trityl (Trt) for Asn, Gln, and His; tert-butylester (O-t-But) for Asp and Glu; tert-butylether (t-But) for Ser, Thr, and Tyr; and 2,2,4,6,7-pentamethyl-dihydrobenzofuran-5-sulfonyl (Pbf) for Arg. Coupling, Fmoc deprotection, cleavage of side chain protecting groups, and peptide recovery were performed as previously described [18].…”

“…The isolation of hLE and hCG was based on the two-step aprotinin-sepharose affinity chromatography and carboxymethyl-cellulose (CMC) ion exchange chromatography developed by Baugh and Travis [25], with slight modifications [18,26]. The enzymatic activity was assayed spectrophoto-Thr-Arg-~ -Gly-Tyr 4 -Ser-I i e-Phe-Ser-Tyr-Ala-Thr-Lys-Arg-Gln-Asp-60…”

“…Recently, we have demonstrated that peptides derived from a specific region within the primary sequence of CRP, containing the core sequence VTVAPVHI (CRP89_96), are potent competitive inhibitors of hLE and hCG in comparison to peptides of similar length corresponding to the active sites of oq-PI and ACT [18]. This core sequence is adjacent to the regulatory peptides CRP77-82, CRP83-90, CRP84 90, and CRP99_103, obtained from the in vitro neutrophilic degradation of CRP [16,17].…”

“…This core sequence is adjacent to the regulatory peptides CRP77-82, CRP83-90, CRP84 90, and CRP99_103, obtained from the in vitro neutrophilic degradation of CRP [16,17]. Increased inhibitory activity towards both hLE and hCG was achieved with an elongation of the N-terminus of CRP89_96 according to the sequence of CRP [18]. Using electrostatic-potential calculations, a prominent positive pocket was illuminated on the surface of hLE which is generated by two exposed positive residues, i.e., Arg 177 and Arg 217.…”

“…Using electrostatic-potential calculations, a prominent positive pocket was illuminated on the surface of hLE which is generated by two exposed positive residues, i.e., Arg 177 and Arg 217. The sequence of CRP contains a glutamic acid moiety in the P7 position (EVTVAPVHI, CRP88_96), which appears to bind into hLE's positive pocket, and subsequently increases inhibitory activity [19]. In contrast to the unique inhibitory capability of CRP-derived peptides, CRP as a whole protein was reported to have no inhibitory effect on hLE [20].…”