Structural information of trypsin isozyme GT-B from grass carp (Ctenopharyngodon idellus) intestines
2008
LIU Zhong-yi | WANG Zhang | XU Shi-ying | ZHANG Jian
In order to learn the correlation between chemical composition, structure and properties of grass carp intestine trypsin isozyme GT-B, the composition of amino acids, characteristic of ultraviolet absorption, and secondary structural units of this enzyme were investigated by instrumental and chemical analytic methods. The amino acids analysis results show that GT-B had a high ratio of acid amino acids to base amino acids, high content of hydrophilic amino acid residue, but low content of cysteine residue and aromatic amino acid residue. GT-B had a weak ultraviolet (UV) absorption at 280 nm. In the presence of denaturing reagent, its absorption increased significantly at 280 nm. According to “di-state model”, its denaturation free energy was calculated to be 39.825 kJ·mol<sup>-1</sup>. The circular dichroism (CD) scanning spectra results indicate that GT-B contained small ratio of α-helix, β-sheet, β-return but most random. By these information, the physical, chemical, dynamical and thermo-dynamical properties of GT-B can be legitimately explained and understood.
显示更多 [+] 显示较少 [-]