Heat shock protein 90ß in the Vero cell membrane binds Japanese encephalitis virus

Wang, Yuan; Li, Yan; Ding, Tianbing

During the Co-IP experiments, unsurprisingly, more than one protein precipitated, and the most notable 3 bands (Fig. 1 ) compared with the controls were subjected to MS analyses. The MS results (Table I) suggested that novel proteins at approximately 95, 43 and 34 kDa are unnamed or hypothetical proteins (scores over 30) based on a monkey protein database (genus Macaca). Due to high genetic homogeneity between monkeys and humans, the human protein database (Homo sapiens) was quested, and the results revealed that the proteins were HSP90β, an unnamed protein, the three-dimensional structure of glutathione s-transferase, and aconitase 2 precursor. Possessing the highest score of 60.3 among the four candidates, HSP90β is an entire, functional protein and was then selected for further investigation, though it is generally considered to be a cytoplasmic protein. Considering the inefficient separation of the hydrophobic and hydrophilic fractions during the cell membrane protein extraction procedures, it was not surprising to discover that a few hydrophilic proteins may be present in the hydrophobic fraction. However, the hydrophobic proteins remained dominant in this fraction. This finding is similar to our previous results when using BHK-21 membrane proteins (36) .