Tuftsin and some analogs: synthesis and interaction with human polymorphonuclear leukocytes.
The phagocytosis-stimulating tetrapeptide tuftsin, L-threonyl-L-lysyl-L-prolyl-L-arginine, was synthesized by both conventional and polymeric-reagent approaches. Using a combination of the two methods several analogs were prepared, including: [Ala1]tuftsin, [Lys1]tuftsin, [Ser1]tuftsin, [Val1]tuftsin, acetyl-tuftsin, p-aminophenylacetyl-tuftsin and tyrosyl-tuftsin. [Des-Thr1]tuftsin and [omega-NO2(4)]tuftsin were synthesized using a conventional procedure. The effects of synthetic peptides on the phagocytosis of heat-killed yeasts and on the reduction of the dye nitroblue tetrazolium by normal human polymorphonuclear leukocytes were investigated. Tuftsin and to a lesser extent [Lys1]tuftsin and [Ser1]tuftsin were found to stimulate phagocytosis, whereas the other analogs synthesized as well as [Ser1]tuftsin exhibited inhibitory effects to tuftsin's action. Tuftsin alone has stimulated nitroblue tetrazolium reduction; [Des-Thr1]tuftsin and [Ala1]tuftsin repressed this stimulation, while the other peptides showed no effect.
D006600:Hexosephosphates / Q000378:metabolism; D006801:Humans; D007128:Immunoglobulin Fragments / Q000494:pharmacology*; D009504:Neutrophils / Q000187:drug effects* / Q000378:metabolism; D009580:Nitroblue Tetrazolium; D010084:Oxidation-Reduction; D010587:Phagocytosis / Q000187:drug effects*; D013329:Structure-Activity Relationship; D014405:Tuftsin / Q000138:chemical synthesis / Q000494:pharmacology*
D006600:Hexosephosphates; D007128:Immunoglobulin Fragments; D009580:Nitroblue Tetrazolium; D014405:Tuftsin