Ghiggeri G M, Candiano G, Ginevri F, Mutti A, Bergamaschi E, Alinovi R, Righetti P G
Nephrology Section, Hospital of Lavagna, Italy.
J Chromatogr. 1988 Oct 28;452:347-57. doi: 10.1016/s0021-9673(01)81459-x.
Alcian Blue (AB), a cationic dye widely employed for monitoring negative surface charge variations on red blood cell (RBC), platelet and glomerular membranes of patients with nephrotic syndromes, was found in fact to aggregate with itself and precipitate in the pH range 7.0-7.8, i.e., at the physiological pH values used for performing the binding assay between the dye and cell surfaces. This aggregation appears to be essentially hydrophobic as it is insensitive to urea but fully prevented in presence of 2% zwitterionic detergent. In addition, AB binds to most RBC membrane proteins solubilized by urea-detergent extraction, again suggesting hydrophobic interaction. AB also interacts with freely soluble proteins such as haemoglobin and myoglobin; such binding is disrupted by ethylurea and/or 2% zwitterionic detergent, typical inhibitors of hydrophobic liaisons. AB also strongly binds to myoglobin with all the negative charges blocked by esterification of the carboxyl groups, again ruling out direct interaction via surface negative charges. It is concluded that AB binding to the RBC surface can hardly monitor variations in surface charge due to sialic acid residues but, at best, variations in surface hydrophobicity.
阿尔辛蓝（AB）是一种阳离子染料，广泛用于监测肾病综合征患者红细胞（RBC）、血小板和肾小球膜表面负电荷的变化。实际上发现，它在pH值7.0 - 7.8范围内，即在用于进行染料与细胞表面结合测定的生理pH值下，会自身聚集并沉淀。这种聚集似乎本质上是疏水性的，因为它对尿素不敏感，但在存在2%两性离子去污剂时能完全防止。此外，AB能与大多数通过尿素 - 去污剂提取而溶解的RBC膜蛋白结合，这再次表明存在疏水相互作用。AB还能与诸如血红蛋白和肌红蛋白等自由可溶性蛋白相互作用；这种结合会被乙基脲和/或2%两性离子去污剂（典型的疏水连接抑制剂）破坏。AB还能与所有羧基被酯化而阻止了所有负电荷的肌红蛋白强烈结合，这再次排除了通过表面负电荷的直接相互作用。得出的结论是，AB与RBC表面的结合很难监测由于唾液酸残基导致的表面电荷变化，充其量只能监测表面疏水性的变化。
