Structural Analysis of Fibroin Heavy Chain Signal Peptide of Silkworm Bombyx mori  

作　　者：Sheng-Peng WANG Ting-Qing GUO Xiu-Yang GUO Jun-Ting HUANG Chang-De LU 

机构地区：[1]Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China [2]Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang 212018, China

出　　处：《Acta Biochimica et Biophysica Sinica》2006年第7期507-513,共7页生物化学与生物物理学报（英文版）

基　　金：This work was supported by the grants from the National Natural Science Foundation of China （No. 30370326 and No. 30470350）

摘　　要：To study the minimal length required for the secretion of recombinant proteins and silk proteins in posterior silk gland, the signal peptide （SP） of the fibroin heavy chain （FibH） of silkworm Bombyx mori was systematically shortened from the C-terminal. Its effect on the secretion of protein was observed using enhanced green fluorescent protein （EGFP） as a reporter. Secretion of EGFP fusion proteins was examined under fluorescence microscope. FibH SPs with lengths of 20, 18, 16 and 12 a.a. can direct the secretion of the reporter, yet those with lengths of 11, 10, 9, 8 and 1 a.a. can not. When the FibH SP was shortened to 12 a.a., the secretion efficiency was decreased slightly and cleavage occurred within EGFP. When 16 a.a. of the FibH SP were used, the secretion of fusion protein was normal and the cleavage site was between the Gly-Ser linker and Met, the starting amino acid of EGFP. These findings are applicable for the expression of foreign proteins in silkworm silk gland. The cleavage site of the SP is discussed and compared with the predictive results of the SignalP 3.0 online prediction program.To study the minimal length required for the secretion of recombinant proteins and silk proteins in posterior silk gland, the signal peptide （SP） of the fibroin heavy chain （FibH） of silkworm Bombyx mori was systematically shortened from the C-terminal. Its effect on the secretion of protein was observed using enhanced green fluorescent protein （EGFP） as a reporter. Secretion of EGFP fusion proteins was examined under fluorescence microscope. FibH SPs with lengths of 20, 18, 16 and 12 a.a. can direct the secretion of the reporter, yet those with lengths of 11, 10, 9, 8 and 1 a.a. can not. When the FibH SP was shortened to 12 a.a., the secretion efficiency was decreased slightly and cleavage occurred within EGFP. When 16 a.a. of the FibH SP were used, the secretion of fusion protein was normal and the cleavage site was between the Gly-Ser linker and Met, the starting amino acid of EGFP. These findings are applicable for the expression of foreign proteins in silkworm silk gland. The cleavage site of the SP is discussed and compared with the predictive results of the SignalP 3.0 online prediction program.

关 键 词：signal peptide fibroin heavy chain silkworm  Bombyx mori rAcMNPV 

分 类 号：Q969[生物学—昆虫学]