Thiolactosyl lipids designed for carbohydrate-protein binding studies have been synthesised. One representative was selected for binding studies with a plant lectin RCA120, the agglutinin from Ricinus communis. The interactions were measured quantitatively in real time using a BIAcore surface plasmon resonance instrument. Removal of much of the galactose from the thiolactosyl lipid in situ with β-galactosidase showed that the lectin binding was highly specific. A dissociation constant KD
= 8.77 à 10â8 M was measured for 1-2-[2-(2-[β-D-galactopyranosyl-(1 â 4)-1-thio-β-D-glucopyranosyl]ethoxy)ethoxy]ethoxy}octadecane 30 which is four orders of magnitude greater than that determined for binding to lactose in solution. A concentration of lactose of >80 mM was required to block the lectin binding to thiolactosyl lipid in a neomembrane.
用于
碳水化合物-蛋白质结合研究的
硫代半
乳糖脂已经合成。其中一种代表被选用于与植物凝集素RC
A120(蓖麻的凝集素)结合的研究。使用BIAcore表面等离子共振仪器实时定量测量了相互作用。用
β-半乳糖苷酶从
硫代半
乳糖脂中原位去除大部分半
乳糖表明凝集素结合具有高度特异性。1-2-[2-(2-[β-
D-半乳糖基-(1 → 4)-1-
硫代-β-
D-吡喃葡萄糖基]乙氧基)乙氧基]乙氧基}
十八烷30的解离常数KD=8.77×10-8 M,比溶液中与
乳糖结合的解离常数高四个数量级。需要浓度大于80mM的
乳糖才能阻止凝集素与新膜中的
硫代半
乳糖脂结合。