Borchman D, Tang D
Department of Ophthalmology and Visual Sciences, University of Louisville, KY 40202, USA.
Exp Eye Res. 1996 Oct;63(4):407-10. doi: 10.1006/exer.1996.0130.
Three experiments were performed to determine the alpha-crystallin binding capacity of bovine lens lipid vesicles. In one experiment lipid was kept constant (2.5 mg ml-1) and the alpha-crystallin concentration was changed (0.5 to 3.0 mg ml-1). In another experiment, alpha-crystallin was kept constant (1 mg ml-1) and the concentration of lipid was varied (0.25 to 3 mg ml-1). We calculated the binding capacity of the lipid to be 0.33 +/- 0.05 (S.D.) mg alpha-crystallin (mg lens lipid)-1. This was confirmed by changes in the anisotropy and fluorescent intensity of a probe that partitions at the headgroup region of the lipid bilayer. Near 0.33 mg alpha-crystallin (mg lens lipid)-1 the fluorescence intensity and anisotropy of the probe increases and plateaus which indicates that concomitant with alpha-crystallin binding, water is excluded from the head group region of the bilayer and the headgroup region becomes less mobile. It is possible that alpha-crystallin binding could protect and stabilize the lipid bilayer and decrease membrane permeability.
进行了三项实验以确定牛晶状体脂质囊泡与α-晶状体蛋白的结合能力。在一项实验中，脂质保持恒定（2.5 mg/ml），α-晶状体蛋白浓度发生变化（0.5至3.0 mg/ml）。在另一项实验中，α-晶状体蛋白保持恒定（1 mg/ml），脂质浓度有所不同（0.25至3 mg/ml）。我们计算得出脂质与α-晶状体蛋白的结合能力为0.33±0.05（标准差）mg α-晶状体蛋白/（mg晶状体脂质）。这通过在脂质双分子层头部区域分配的探针的各向异性和荧光强度变化得到了证实。在接近0.33 mg α-晶状体蛋白/（mg晶状体脂质）时，探针的荧光强度和各向异性增加并趋于平稳，这表明随着α-晶状体蛋白的结合，水被排除在双分子层的头部区域之外，且头部区域的流动性降低。α-晶状体蛋白的结合有可能保护和稳定脂质双分子层并降低膜通透性。
