| Research Abstract |
A neuropeptide (s) showing the same activity as a summer-morph-producing hormone of the Asian comma butterfly, P.c-aureum, was found to exist in brain-suboesophageal ganglion (Br-SG) extract of the silkmoths, Bombyx mori. The peptide was almost the same molecular size with that of bombyxin activating the prothoracic glands of 4th-instar B.mori larvae in vitro.
A Sephadex G-50 fraction of Br-SG extracts of B.mori involving molecules of 3-8 kD was applied on CM-, SP-, DEAE- and QAE- Toyoperal columns at pH 5.6 (or pH 6.9), respectively. The SMPH-active peptide was bound to, but bombyxin was not bound to, anion-exchange columns at pH 6.9.By anion-exchange chromatography with a Mono-Q column, the SMPH-activity was recovered in a different fraction from that of bombyxin. A SMPH-active fraction eluted from an Accell QMA cartridge following a Sephadex G-50 column was applied to a reversed-phase HPLC with a linear gradient of 0-50% acetonitoril/50 min (pH 6.9).The SMPH-activity was recovered in two fractions of 40-45% acetonitoril, where only one major peptide band of 2.5-6 kD was stained by SDS-PAGE.
The results indicated that a neuropeptide responsible for SMPH-activity of Br-SG extracts of B.mori adults is different from that of bombyxin. The neuropeptide can be purified further by subjecting SMPH-active preparation to anion-exchange chromatography and SDS-PAGE.
In addition, some other results was summarized in this reports. They were obtained using the instruments which were supplied by this grant.
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