Structure,function and movement of insect brain peptides,particularly prothoracicotropic hormone.

1.通过对纯化的家蚕促前胸腺激素(PTTH)进行测序和cDNA分子克隆相结合，确定了家蚕促前胸腺激素(PTTH)的一级结构。家蚕促前胸腺激素由两条相同的多肽链组成，每条链由109个氨基酸残基和41位天冬酰胺结合的糖链组成。利用大肠杆菌系统获得具有生物活性的重组PTTH，并用重组PTTH2确定PTTH的二硫键位置。建立了高效合成家蚕毒素这一胰岛素家族多肽的方法，并合成了家蚕毒素及其类似物，通过核磁共振分析确定了家蚕毒素及其类似物的三级结构。对羽化激素(EH)和信息素生物合成激活神经肽(PBAN)的cDNAs进行了测序，发现PBAN基因除编码PBAN外，还编码滞育激素和三个可能的酰胺化多肽。测定了家蚕脂肪运动激素的一级结构和滞育激素的N末端序列。免疫化学研究显示，甲状旁腺素、家蚕素和PBAN产生神经分泌细胞。

1. The primary structure of Bombyx prothoracicotropic hormone(PTTH)was determined by combination of sequencing of the purified PTTH and molecular cloning of cDNA.Bombyx PTTH consists of two identical peptide chains which are held together by disulfide bond(s),and each chain is composed of 109 amino acid residues and a carbohydrate chain bound to an asparagine at position 41.The biologically active,recombinant PTTH has been obtained by using the Escherichia coli system and the disulfide bond location of PTTH were determined using recombinant PTTH.2. The highly effective method for synthesis of bombyxins,an insulin-family peptide,mainly focusing on the selective formation of three disulfide bonds was established,and bombyxin and its various analogs were synthesized.The tertiary structure of bombyxin and its analogs will be determined by NMR analysis.The cDNAs of bombyxin-related peptide were isolated from Samia cynthia ricini and Agrius convolvuri.3. The cDNAs of eclosion hormone(EH)and pheromone biosynthesis activating neuropeptide (PBAN)has been sequenced.PBAN cDNA encodes,besides PBAN,diapause hormone and three putative amidated peptides.4. The primary structure of Bombyx adipokinetic hormone and the N-terminal sequence of diapause hormone were determined.5. The immunochemical studies revealed PTTH-,bombyxin-and PBAN-producing neurosecretory cells.