Tween protects recombinant human growth hormone against agitation-induced damage via hydrophobic interactions
Tween protects recombinant human growth hormone against agitation-induced damage via hydrophobic interactions
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DOI：
10.1021/js980175v
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发表时间：
1998-12-01
影响因子：
3.8
通讯作者：
Randolph, JW
中科院分区：
文献类型：
--
作者：
Bam, NB;Cleland, JL;Randolph, JW
在不存在表面活性剂的情况下，重组人生长激素（rhGH）在搅拌过程中迅速形成不溶性聚集体。非离子表面活性剂Tween 20，当以Tween：蛋白质摩尔比> 4存在时，有效地抑制这种聚集。rhGH溶液的差示扫描量热法（DSC）显示熔融转变降低约。在Tween的存在下2 ℃。相同的热转变的圆二色性（CD）研究表明，减少是特定的相对较高的蛋白质浓度所需的DSC。CD研究显示，随着蛋白质浓度的降低，熔融转变降低。在较低蛋白浓度（0.18 mg/mL）下，吐温对rhGH的熔融转变影响不显著。注射滴定微量热法表明，吐温与rhGH的相互作用的特点是由一个弱的结合焓。为了比较，干扰素-g，另一种已经显示出结合吐温的蛋白质，也显示出弱的结合焓。rhGH二级结构的荧光探针结合研究和红外光谱研究支持文献中的建议（Bam，N. B.; Cleland，J.L.，兰多夫，T。W.重组人生长激素的熔融球中间体：表面活性剂的稳定作用。Biotechnol.青蛙1996. 12，801-809），吐温结合是由疏水相互作用驱动的，对蛋白质二级结构几乎没有扰动。
In the absence of surfactants, recombinant human growth hormone (rhGH) rapidly forms insoluble aggregates during agitation. The nonionic surfactant Tween 20, when present at Tween:protein molar ratios > 4, effectively inhibits this aggregation. Differential scanning calorimetry (DSC) of rhGH solutions showed melting transitions that decreased by ca. 2 degrees C in the presence of Tween. Circular dichroism (CD) studies of the same thermal transition showed that the decrease is specific to the relatively high protein concentrations required for DSC. CD studies showed melting transitions that decreased with lower protein concentrations. Tween has an insignificant effect on the melting transition of rhGH at lower protein concentrations (0.18 mg/mL). Injection titration microcalorimetry showed that the interaction of Tween with rhGH is characterized by a weak enthalpy of binding. For comparison, interferon-g, another protein which has been shown to bind Tween, also shows weak enthalpy of binding. Fluorescent probe binding studies and infrared spectroscopic investigations of rhGH secondary structure support suggestions in the literature (Bam, N. B.; Cleland, J. L., Randolph, T. W. Molten globule intermediate of recombinant human growth hormone: stabilization with surfactants. Biotechnol. Frog. 1996. 12, 801-809) that Tween binding is driven by hydrophobic interactions, with little perturbation of protein secondary structure.