Ca2+离子对榛子过敏原Cor h 1二级结构和抗原活性影响研究

目的:研究Ca2+离子对非CaBPs蛋白类过敏原二级结构和抗原活性的影响。方法:以重组榛子主要过敏原Cor h 1为研究对象,用圆二色谱(CD)研究了系列浓度的Ca2+和EDTA各自存在情况下,不同蛋白浓度溶液中rCor h 1二级结构的变化及规律,并以榛子过敏患者血清为一抗,用ELISA实验分析了Ca2+和EDTA对rCor h 1抗原活性的影响。结果:在高浓度rCor h 1溶液中Ca2+的加入可以引起椭圆率的增加,而在低浓度的rCor h 1溶液中则引起椭圆率的降低;EDTA在高浓度和低浓度的rCor h 1溶液中均能引起rCor h 1二级结构相对含量的降低;椭圆率增加(或降低)的幅度与Ca2+、EDTA终浓度成正比。ELISA实验表明Ca2+和EDTA都能显著降低rCor h 1的抗原活性。结论:Ca2+离子可以显著影响rCor h 1的二级结构,降低其抗原活性,为非CaBPs蛋白类低致敏原的研究奠定了较好的前期研究基础。

Effects of Ca2+-binding on the secondary structure and antigen binding activity of Cor h 1,a major allergen from Corylus Heterophylla

Objective: To investigate the Ca2+-binding properties of allergen proteins which have no"EF-hand"sites,thus being responsible of the effect of Ca2 + binding on the development of hypoallergens.Methods: For the experiment,recombinant Cor h 1,a major allergen from hazelnet(Corylus Heterophylla),was used.Conformational analysis(CD) and specific immunodetection assay(ELISA) were performed in the presence of Ca2+ and EDTA respectively.Results: It was shown that considerable increases and loss in ellipticity in high and low concentrations rCor h 1 solutions were observed respectively in the presence of Ca2 +.But the addition of EDTA resulted in a loss of regular secondary structure in both high and low concentrations.rCor h 1 displays IgE-binding activities against sera of patients allergic to hazelnut.Both in the presence of Ca2 + and EDTA,remarkable decrease in the binding properties between rCor h 1 and IgE was examined.Conclusion: The secondary structure and antigen binding activity of rCor h 1 were affected by Ca2 +-binding or not notably.And the Ca2 +-binding and Ca2 +-free proteins many be considered when desiging hypoallergenin derivatives to be used in immunotherapy.