Abstract

Investigation of immunoglobulin (IgG) solutions with the concentration of 0.125 mg/mL shows that monomer IgG macromolecules ~10 nm in size form aggregates as large as ~300 nm in water and ~900 nm in the 36.7 vol % ethanol–water mixture (EWM). Shaking results in formation of floating-up bubbles in the solutions of both types. However, efficiency of immunoglobulin bubble flotation in water and EWM is substantially different. This difference can be caused by simultaneous action of two mechanisms for attachment of IgG particles (macromolecules or aggregates) to bubbles in aqueous solutions: direct attraction of IgG particles to the charged surface of a bubble and existence of ion-stabilized nanobubbles with a radius of ~100 nm capable of making up compound particles like nanobubbles–IgG macromolecules/IgG aggregates, which in turn serve as “spatial agents” for flotation of IgG particles on larger bubbles. In the EWM, attachment of IgG particles to floating-up bubbles is ineffective because of weak surface charge of macro- and microbubbles and absence of nanobubbles.

中文翻译：

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水和醇水混合物中蛋白质的聚集和浮选特性

摘要

对浓度为0.125 mg / mL的免疫球蛋白（IgG）溶液的研究表明，大小约为10 nm的单体IgG大分子在水中的聚集体最大可达〜300 nm，而在36.7 vol％的乙醇-水混合物（EWM ）。摇动会导致在两种类型的溶液中形成上浮气泡。但是，免疫球蛋白气泡在水中和EWM中的浮选效率有很大不同。这种差异可能是由于两种将IgG颗粒（大分子或聚集体）附着到水溶液中的气泡的同时作用引起的：IgG颗粒直接吸引到气泡的带电表面上，并且存在半径为的离子稳定的纳米气泡。约100 nm能够组成化合物颗粒，例如纳米气泡– IgG大分子/ IgG聚集体，反过来又充当“空间剂”，用于在较大气泡上浮选IgG颗粒。在EWM中，由于大气泡和微气泡的表面电荷较弱，而没有纳米气泡，因此IgG颗粒与漂浮气泡的附着是无效的。