Sialokinin I and II: vasodilatory tachykinins from the yellow fever mosquito Aedes aegypti.
The saliva of the mosquito Aedes aegypti has previously been reported to contain a 1400-Da peptide with pharmacological properties typical of a tachykinin. In the present study this vasodilator has been purified to homogeneity and found to consist of two peptides: sialokinin I, with the sequence Asn-Thr-Gly-Asp-Lys-Phe-Tyr-Gly-Leu-Met-NH2, and sialokinin II, identical to sialokinin I except for an Asp in position 1. These peptides are present in amounts of 0.62 and 0.16 pmol (711 and 178 ng), respectively, per salivary gland pair. When assayed on the guinea pig ileum, both peptides are as active as the mammalian tachykinin substance P, with K0.5 values of 5.07, 6.58, and 4.94 nM for sialokinin I, sialokinin II, and substance P, respectively.
Champagne
D E
DE
Department of Entomology, University of Arizona, Tucson 85721.
Ribeiro
J M
JM
D000330:Aedes / Q000737:chemistry*; D000595:Amino Acid Sequence; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D008969:Molecular Sequence Data; D012471:Salivary Proteins and Peptides / Q000737:chemistry / Q000494:pharmacology; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D015320:Tachykinins / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D014665:Vasodilator Agents
D012471:Salivary Proteins and Peptides; D015320:Tachykinins; D014665:Vasodilator Agents; C085110:sialokinin I; C085111:sialokinin II