Inactivation of C5a anaphylatoxin by a peptide that is complementary to a region of C5a.
PL37 (RAARISLGPRCIKAFTE) is an antisense homology box peptide composed of aa 37-53 of C5a-anaphylatoxin and is considered to be the region essential for C5a function. Using a computer program, we designed the complementary peptides ASGAPAPGPAGPLRPMF (Pep-A) and ASTAPARAGLPRLPKFF (Pep-B). Pep-A bound to PL37 and to C5a with very slow dissociation as determined by analysis using surface plasmon resonance, whereas Pep-B failed to bind at all. C5a was inactivated by concentrations of 7 nM or more of Pep-A, and this concentration of Pep-A inhibited induction of intracellular Ca(2+) influx in neutrophils. Patch clamp electrophysiology experiments also showed the effectiveness of Pep-A in C5aR-expressing neuroblastoma cells. Furthermore, Pep-A administration prevented rats from C5a-mediated rapid lethal shock induced by an Ab to a membrane inhibitor of complement after LPS sensitization.
Fujita
Emiko
E
Department of Biodefense, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.
Farkas
Imre
I
Campbell
William
W
Baranyi
Lajos
L
Okada
Hidechika
H
Okada
Noriko
N
D000595:Amino Acid Sequence; D000707:Anaphylaxis / Q000401:mortality / Q000517:prevention & control; D000818:Animals; D000941:Antigens / Q000737:chemistry / Q000378:metabolism / Q000502:physiology; D016375:Antisense Elements (Genetics) / Q000138:chemical synthesis / Q000378:metabolism / Q000502:physiology; D002118:Calcium / Q000378:metabolism; D045744:Cell Line, Tumor; D002469:Cell Separation; D015936:Complement C5a / Q000037:antagonists & inhibitors* / Q000378:metabolism* / Q000502:physiology; D003169:Complement Inactivator Proteins / Q000138:chemical synthesis / Q000378:metabolism / Q000502:physiology*; D004195:Disease Models, Animal; D006801:Humans; D007424:Intracellular Fluid / Q000378:metabolism; D008297:Male; D008969:Molecular Sequence Data; D009504:Neutrophils / Q000276:immunology / Q000378:metabolism; D018408:Patch-Clamp Techniques; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000378:metabolism / Q000502:physiology*; D011485:Protein Binding / Q000276:immunology; D051381:Rats; D017208:Rats, Wistar
D000941:Antigens; D016375:Antisense Elements (Genetics); D003169:Complement Inactivator Proteins; D010446:Peptide Fragments; D015936:Complement C5a; D002118:Calcium