title: Rigin, another phagocytosis-stimulating tetrapeptide isolated from human IgG. Confirmations of a hypothesis.
abstract: Structure-function and conformational studies of the molecule of phagocytosis-stimulating tetrapeptide tuftsin permitted the conclusion that among products resulting from splitting of H-chain of IgG Human EU by trypsin, besides tuftsin (sequence 289-292), tuftsin-like tetrapeptide Gly-Gln-Pro-Arg may be also present; theoretical conformational analysis shows a considerable similarity of spatial arrangement of this tetrapeptide and tuftsin which testifies in favour of potential tuftsin-like activity of the tetrapeptide. Gly-Gln-Pro-Arg was synthesized and its phagocytosis stimulating activity was found equal to that of tuftsin.
mesh_terms: D000595:Amino Acid Sequence; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis*; D009842:Oligopeptides / Q000032:analysis; D010587:Phagocytosis / Q000187:drug effects*; D011487:Protein Conformation; D014357:Trypsin / Q000378:metabolism; D014405:Tuftsin / Q000032:analysis
chemical_list: D007074:Immunoglobulin G; D009842:Oligopeptides; D014357:Trypsin; D014405:Tuftsin; C031491:rigin