Della Ventura Bartolomeo, Schiavo Luigi, Altucci Carlo, Esposito Rosario, Velotta Raffaele
Biomed Opt Express. 2011 Nov 1;2(11):3223-31. doi: 10.1364/BOE.2.003223. Epub 2011 Oct 28.
Ultrashort UV pulses at 258 nm with repetition rate of 10 kHz have been used to irradiate buffer solution of antibody. The tryptophan residues strongly absorb this radiation thus becoming capable to disrupt the disulfide bridges located next to them. Due to their high reactivity the opened bridges can anchor a gold plate more efficiently than other sites of the macromolecule giving rise to preferential orientations of the variable part of the antibody. UV irradiation has been applied to anchor antiIgG antibody to the electrode of a Quartz Crystal Microbalance (QCM) that lends itself as a sensor, the antibody acting as the bio-receptor. An increase of the QCM sensitivity and of the linear range has been measured when the antibody is irradiated with UV laser pulses. The photo-induced reactions leading to disulfide bridge breakage have been analyzed by means of a chemical assay that confirms our explanation. The control of disulfide bridges by UV light paves the way to important applications for sensing purpose since cysteine in combination with tryptophan can act as a hook to link refractory bio-receptors to surfaces.
已使用波长为258 nm、重复频率为10 kHz的超短紫外脉冲辐照抗体缓冲溶液。色氨酸残基强烈吸收这种辐射，从而能够破坏其附近的二硫键。由于其高反应活性，打开的二硫键比大分子的其他部位更有效地锚定金板，从而导致抗体可变部分的优先取向。已应用紫外辐照将抗IgG抗体固定到石英晶体微天平（QCM）的电极上，该石英晶体微天平可用作传感器，抗体作为生物受体。当用紫外激光脉冲辐照抗体时，测量到QCM灵敏度和线性范围有所增加。通过化学分析对导致二硫键断裂的光诱导反应进行了分析，证实了我们的解释。紫外光对二硫键的控制为传感目的的重要应用铺平了道路，因为半胱氨酸与色氨酸结合可作为将难固定的生物受体连接到表面的钩子。
