Raghu Pullakhandam, Ghosh Sudip, Soundarya Kanukolanu, Haseeb Abdul, Aruna Battu, Ehtesham Nasreen Z
Molecular Biology Unit, National Institute of Nutrition (ICMR), Jamai-Osmania, Hyderabad 500007, India.
Biochem Biophys Res Commun. 2004 Jan 16;313(3):642-6. doi: 10.1016/j.bbrc.2003.11.156.
Resistin, an adipocyte secreted cysteine rich hormone has been implicated as molecular link between obesity and type 2 diabetes in a murine model. Although, at the protein level mouse and human resistin show remarkable similarities with respect to conserved cysteine residues, the physiological role of human resistin is not yet clear. In the present study we describe the purification and refolding of human recombinant resistin using two different refolding processes. Gel filtration analysis of protein refolded by both the methods revealed that human recombinant resistin, like mouse resistin, has a tendency to form dimers. Interestingly, dimerization of resistin appears to be mediated by both covalent (disulfide bond mediated) and non-covalent interactions as seen on reducing and non-reducing SDS-PAGE. Circular dichroism spectral analysis revealed that human resistin peptide backbone is a mixture of alpha-helical and beta-sheet conformation with significant amounts of unordered structure, similar to the mouse resistin. It is likely that the first cysteine (Cyst22) of human resistin, which is equivalent to mouse Cyst26, may be involved in stabilizing the dimers through covalent interaction.
抵抗素是一种由脂肪细胞分泌的富含半胱氨酸的激素，在小鼠模型中，它被认为是肥胖与2型糖尿病之间的分子纽带。尽管在蛋白质水平上，小鼠和人类的抵抗素在保守半胱氨酸残基方面表现出显著相似性，但人类抵抗素的生理作用尚不清楚。在本研究中，我们描述了使用两种不同的复性方法对重组人抵抗素进行纯化和复性的过程。对通过两种方法复性的蛋白质进行凝胶过滤分析表明，重组人抵抗素与小鼠抵抗素一样，有形成二聚体的倾向。有趣的是，在还原型和非还原型SDS-PAGE上可以看到，抵抗素的二聚化似乎是由共价（二硫键介导）和非共价相互作用介导的。圆二色光谱分析表明，人抵抗素肽主链是α-螺旋和β-折叠构象的混合物，还有大量无规结构，这与小鼠抵抗素相似。人抵抗素的第一个半胱氨酸（Cyst22，相当于小鼠的Cyst26）可能通过共价相互作用参与稳定二聚体。
