AF2, an Ascaris neuropeptide: isolation, sequence, and bioactivity.
A FMRFamide-like neuropeptide, KHEYLRFamide (Lys-His-Glu-Tyr-Leu-Arg-Phe-amide; AF2) was isolated from a head extract of the nematode Ascaris suum by using a three-step HPLC separation. In a dorsal muscle strip preparation, synthetic AF2 produced multiple effects on muscle tension: a slow relaxation was followed by contraction and rhythmic activity. Sulfated AF2 was no more potent than AF2. The effects on muscle tension were correlated with electrical activity recorded intracellularly from muscle cells. AF2 markedly increased the tension change associated with change in muscle membrane potential.
Cowden
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Department of Zoology, University of Wisconsin, Madison 53706.
Stretton
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D000200:Action Potentials / Q000502:physiology; D000595:Amino Acid Sequence; D000818:Animals; D017165:Ascaris suum / Q000737:chemistry* / Q000502:physiology; D066298:In Vitro Techniques; D008969:Molecular Sequence Data; D009119:Muscle Contraction / Q000502:physiology; D009126:Muscle Relaxation / Q000502:physiology; D009129:Muscle Tonus / Q000502:physiology; D009479:Neuropeptides / Q000737:chemistry / Q000302:isolation & purification* / Q000502:physiology
D009479:Neuropeptides; C073964:AF2 neuropeptide