Fontaine M, Aubert J P, Joisel F, Lebreton J P
Mol Immunol. 1982 Jan;19(1):27-37. doi: 10.1016/0161-5890(82)90242-5.
Charge shift electrophoresis and crossed hydrophobic interaction immuno-electrophoresis were used to demonstrate the presence of hydrophobic sites in the human C3 molecule. C3b and C3d were true amphiphilic proteins that could bind to hydrophobic surfaces. To the contrary, native C3, that presented the characteristics of amphiphilic proteins upon charge shift electrophoresis, did not bind to hydrophobic surfaces. These results suggested that the hydrophobic sites were located in the internal part of the C3 molecule and they were exposed in the external part when C3 was activated. The action of chaotropes on C3 was studied in detail and showed that the hydrophobic sites protected the thiolester bond (present in the labile site) from hydrolysis by water and thereby preserved the biological properties of native C3.
采用电荷转移电泳和交叉疏水相互作用免疫电泳来证明人C3分子中存在疏水位点。C3b和C3d是真正的两亲性蛋白质，能够结合疏水表面。相反，在电荷转移电泳中呈现两亲性蛋白质特征的天然C3并不结合疏水表面。这些结果表明，疏水位点位于C3分子的内部，当C3被激活时它们暴露于外部。对离液剂对C3的作用进行了详细研究，结果表明疏水位点可保护硫酯键（存在于不稳定位点）免受水的水解，从而保留天然C3的生物学特性。
