表面等离子体共振成像法用于糖蛋白分析

建立了一套表面等离子体共振成像方法, 用于筛选糖蛋白和非糖蛋白, 并可以区分不同糖蛋白与伴刀豆凝集素的识别强度. 波长调制的表面等离子体共振与成像法所得结果一致. 伴刀豆凝集素的洗脱成像实验为识别强度提供了补充验证方案.

Glycoproteins Analysis by Surface Plasmon Resonance Absorption and Imaging

Surface plasmon resonance(SPR) absorption and imaging(SPRI) have been explored for screening and differentiating glycoproteins from non-glycoprotein according to the shift of maximum SPR absorption and/or to the variation of picture gray intensity. In combination with competitive washing with sugar solutions, SPRI has the ability to produce different signals for different gylcoproteins, offering a potential way to identify these gylcoconjugates. To conduct SPR and SPRI, proteins(at 1.0 mg/mL), in stead of lectins, were immobilized on gold sensing films to reduce the use of the costly glycoproteins. The sensing film was fixed in a laboratory-established SPR or SPRI system, equilibrated with 50 mmol/L Tris-HCl at pH=7.4 at a flow rate of 20 μL/min, reacted with 200 nmol/L ConA(prepared in the Tris-HCl solution containing 120 mmol/L NaCl, 25 mmol/L CaCl2 and 5 mmol/L MnCl2) at room temperature for 1 h and rewashed with Tris-HCl solution. For competitive washing, 80 mmol/L glucose solution was pumped into the analytical cell and reacted for 1 h. The signals were recorded whenever necessary. Non-gylcoproteins had no signals when using either SPR or SPRI while glycoproteins gave different SPR shifts and gray intensity in SPRI.