纳米/微米一水草酸钙、二水草酸钙对牛血清白蛋白的吸附性能  

Adsorption Properties of Bovine Serum Albumin on Micron/Nano Calcium Oxalate Monohydrate and Dihydrate Crystals

作　　者：温小玲[1,2] 欧阳健明[1,2] 

机构地区：[1]暨南大学生物矿化与结石病防治研究所 [2]暨南大学化学系,广州510632

出　　处：《无机化学学报》2016年第1期103-110,共8页Chinese Journal of Inorganic Chemistry

基　　金：国家自然科学基金(No.21371077)资助项目

摘　　要：研究了牛血清白蛋白(BSA)在尺寸分别为100 nm、3μm的一水草酸钙(COM)和二水草酸钙(COD)晶体上的吸附等温线及晶体ζ电位随BSA浓度(cBSA)的变化。结果表明,4种晶体对BSA的最大吸附量顺序为COD-100 nm>COM-100 nm≥COD-3μm>COM-3μm,即吸附量与晶体的比表面积成正相关。而比表面积归一化后,吸附量顺序为COD-3μm>COM-3μm>COM-100 nm>COD-100 nm,说明COM和COD晶体的结晶水数量和晶面电荷密度影响了BSA的吸附。吸附等温线都很好地拟合了Langmuir模型,表明BSA在纳米/微米COM、COD晶体上的吸附属于单分子层吸附。COM和COD等电点大小顺序为COM-100 nm(7.2)>COD-100 nm(6.7)≥COM-3μm(4.7)>COD-3μm(4.3),因此在病生理条件下(p H≈6.3)纳米级晶体的团聚比微米级晶体的更严重。纳米级和微米级晶体对BSA的最大吸附量都在BSA等电点附近(p H=4.8)。BSA在纳米/微米COM和COD晶体上的吸附与晶体的比表面积、晶面电荷、团聚、结晶水数量和pH值有关。本文结果有助于阐明尿液中不同性质微晶与尿蛋白质对草酸钙结石形成的影响。The adsorption isotherms of bovine serum albumin（BSA） on calcium oxalate monohydrate（COM） and calcium oxalate dehydrate（COD） crystals with a size of 100 nm and 3 μm were detected, and Zeta potential of the crystals after adsorption of various concentration of BSA was measured. Adsorption quality change of BSA at different p H value were also measured. Results showed that the adsorption quality of BSA were positively related to the specific surface area of crystals, that was, following the order： COD-100nm〉COM-100 nm≥COD-3 μm〉COM-3μm. However, after surface area normalization, the adsorption order was COD-3 μm 〉COM-3 μm 〉COM-100 nm 〉COD-100 nm. It indicated that the crystal water and charge density on crystal surface of COM and COD also affected BSA adsorption. These adsorption isotherms were fitted better with Langmuir model, indicating a monolayer adsorption of BSA on micron/nano COD and COM surface. The isoelectric point of the four crystals followed an order：COM-100 nm（7.2） 〉COD-100 nm（6.7） ≥COM-3 μm（4.7） 〉COD-3 μm（4.3）, which indicated more serious aggregation of nanocrystals under pathophysiological conditions（p H≈6.3）. The maximum BSA adsorption occurred at around isoelectric point of BSA（p H=4.8）. The adsorption of BSA on micron/nano COM is related to the specific surface area of crystals, its surface charge, crystal aggregation, crystal water number, and the pH value of system.These results can help to clarify the effect of various urine microcrystalline and urine proteins on the formation of CaO_x stones.

关 键 词：纳米 微米 草酸钙 牛血清白蛋白 吸附等温线 等电点 pH值 

分 类 号：O614.231[理学—无机化学]