Increased Inhibitory Capacity of an Anti‐C5a Complementary Peptide Following Acetylation of N‐terminal Alanine

Abstract

Amino acids 37 to 53 (RAARISLGPRCIKAFTE) of C5a anaphylatoxin form an essential region for C5a function. To target this sequence, we generated a complementary peptide (ASGAPAPGPAGPLRPMF) designated PepA which has a potent inhibitory effect on C5a activity. By introducing an acetyl group at the N‐terminal alanine of PepA, an acetylated form was generated which was designated AcPepA. The acetylation resulted in increased inhibition of C5a stimulation of neutrophils as determined by Ca influx. Furthermore, AcPepA partially inhibited the lethal shock induced in mice by intravenous administration of Candida albicans water‐soluble mannoprotein‐β‐glucan complex. In addition, local skin inflammation in rats caused by an anti‐Crry monoclonal antibody was suppressed when AcPepA and the antibody were injected together, while PepA had little inhibitory capacity. The potent inhibitory capacity of AcPepA was also confirmed by a skin reaction of guinea pigs inoculated with recombinant human C5a together with AcPepA.

Anti-C5a complementary peptide ameliorates acute peritoneal injury induced by neutralization of Crry and CD59

“…As a result, it was considered that further complement activation might be suppressed and that C3b deposi- tion was decreased; therefore, we considered that C5a might be a target of therapeutic approaches for peritoneal injury. In the present study, we used a complementary small peptide, AcPepA, previously reported to prevent the role of C5a (30). AcPepA was also reported to be a powerful C5a inhibitor capable of blocking C5a in septic monkeys (29).…”

“…FITC-labeled polyclonal goat anti-rat C3b was purchased from Cappel (Solon, OH). AcPepA was generated according to our previous report (30). A C5aR antagonist (C5aRA) hexapeptide, NMePhe-Lys-Pro-dCha-Trp-dArg (synthesized by the Peptide Institute, Osaka, Japan) was originally reported by Konteatis et al (15) and has been confirmed to inhibit C5a activation in animal models (14,27).…”

“…A 17-amino acid complementary peptide for C5a, PepA, directly bound to C5a and blocked the effects of C5a, and showed protective effects in a lipopolysaccharide-associated lethal shock model in rat (8,27). Recently, an acetylated form of PepA (AcPepA) was generated to improve the inhibition capacity of PepA (30). AcPepA prevented acute skin inflammation (30) and acute rejection of islet transplantations in models (38).…”

“…Recently, an acetylated form of PepA (AcPepA) was generated to improve the inhibition capacity of PepA (30). AcPepA prevented acute skin inflammation (30) and acute rejection of islet transplantations in models (38).…”

HMGB1 Release by C5a Anaphylatoxin is an Effective Target for Sepsis Treatment

“…We generated an inhibitory peptide of C5a composed of an amino acid sequence ASGAPAPGPAGPLRPMF named PepA [3]. Acetylation at the N-terminal alanine of PepA improved the C5a inhibitory capacity and was named AcPepA [4].…”