Title
Functional and structural properties of red color–related pigment–binding protein from the shell of Litopenaeus vannamei
Author
Pan Chuang, Shoichiro Ishizaki, Yuji Nagashima, Shugo Watabe
Year
2018
Journal
Journal of the Science of Food and Agriculture
Abstract
A novel red color–related pigment–binding protein, named LvPBP75, isolated from the shell of Litopenaeus vannamei has recently been identified as hemocyanin. However, information on the functional and structural properties of LvPBP75 is insufficient. This study was aimed to elucidate the thermal properties and pigment–binding ability of LvPBP75. LvPBP75 showed significant red color change after heat treatments with high concentration of NaCl (> 0.1 M), acidic (< pH 5) or alkaline (> pH 9) pHs, and alcohols. LvPBP75 mRNA expression analysis revealed that expression level was highest in hepatopancreas and weakest in muscle. Reconstruction and structural analysis revealed that astaxanthin could bound to the hemocyanin derived from the shell of L. vannamei, but not the hemocyanins derived from hepatopancreas or hemolymph of other invertebrates. Three–dimensional models of hemocyanin monomer displayed significant structural differences between native LvPBP75 and hemocyanin derived from shrimp hepatopancreas. Our results suggest a novel function of hemocyanin as binding with pigment and its involvement in L. vannamei shell color change. The pigment–binding ability of hemocyanins has species– and tissue–specificity and their unique structural features play an important role in binding ability.
Instrument
J-725
Keywords
Circular dichroism, Secondary structure, Chemical stability, Thermal stability, Biochemistry