作者机构：
Hunan Normal Univ, Coll Life Sci, Changsha 410081, Peoples R China.;Hunan Agr Univ, Dept Biol Technol, Changsha 410128, Peoples R China.;[Wang, XC; Liang, SP] College of Life Science, Hunan Normal University, Changska 410081, China;[Luo, ZM] Department of Biological Technology, Hunan Agricultural University, Changsha 410128, China
通讯机构：
[Wang, Xian-Chun] C;College of Life Science, Hunan Normal University, Changsha 410081, China.
摘要：
The functional amino acid sequence and its neighbouring fragments in the molecule of Amaranth α-amylase inhibitor isolated from seeds of the Mexican crop plant Amaranthus hypochondriacus were transferred, by solid phase chemical synthesis, into N-terminal region of the huwentoxin-I (HWTX-I). The synthetic chimera polypeptide was confirmed by Edman degradation and MALDI-TOF mass spectroscopy. The formation of three disulfide bonds and special conformation of the synthetic chimera was induced by the addition of glutathione. Renatured chimera polypeptide was purified by ion-exchange and reversed phase HPLC. The results showed that the engineered chimera polypeptide exerted obvious inhibitory activity to α-amylase from digestive tube of the roach (Periplaneta americana ) at pH 5.5 with the concentration of 9.5×10-5 mol/L, and also exerted 36% of the neurotoxic activity of the natural huwentoxin-I as shown by the experiments of blockage of the neuromuscular transmission of isolated mouse phrenic nerve-diaphragm preparations. The experiments demonstrated that the structural motif of HWTX- I is well promising for protein engineering, and the solid-phase peptide synthesis is adequate rapid for the engineering of artificially designed small proteins.
