Prothoracicotropic hormone of the silkworm, Bombyx mori: amino acid sequence and dimeric structure.
Prothoracicotropic hormone (PTTH) of the silkworm, Bombyx mori, was purified and its primary structure determined for the most part. From sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the purified PTTH under non-reducing and reducing conditions, and the amino acid sequence and composition analyses of the carboxamidomethylated PTTH, we concluded that Bombyx PTTH has a dimeric structure consisting of two identical, or nearly identical subunits, held together by disulfide bond(s). There exist subunit variants that differ by deletion of only a few amino acid residues at the N-terminus, and possibly at the C-terminus also, giving rise to a high heterogeneity in the PTTH molecule. The amino acid sequence up to the 104th residue from the N-terminus of the longest subunit, except for the 41st residue, was determined by sequence analysis of fragment peptides produced by lysyl endopeptidase, chymotrypsin and V8 protease digestions, leaving only a short C-terminal sequence undetermined. Bombyx PTTH is expected to contain a carbohydrate chain bound to an asparagine at position 41, deduced from the cDNA sequence.
Department of Agricultural Chemistry, Faculty of Agriculture, University of Tokyo, Japan.
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H
Kataoka
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Nagasawa
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Isogai
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H
Ishizaki
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Suzuki
D000595:Amino Acid Sequence; D000818:Animals; D001704:Biopolymers; D012831:Bombyx / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D002918:Chymotrypsin; D004591:Electrophoresis, Polyacrylamide Gel; D007301:Insect Hormones / Q000737:chemistry*; D008297:Male; D008969:Molecular Sequence Data; D009479:Neuropeptides / Q000737:chemistry*; D012697:Serine Endopeptidases
D001704:Biopolymers; D007301:Insect Hormones; D009479:Neuropeptides; C009089:prothoracicotropic hormone; D012697:Serine Endopeptidases; D002918:Chymotrypsin; C028344:glutamyl endopeptidase; C036813:lysyl endopeptidase