Borromeo Vitaliano, Sereikaite Jolanta, Bumelis Vladas-Algirdas, Secchi Camillo, Scirè Andrea, Ausili Alessio, D'Auria Sabato, Tanfani Fabio
Department of Animal Pathology and Health, Faculty of Veterinary Medicine, University of Milan, Milan, Italy.
Protein J. 2008 Apr;27(3):170-80. doi: 10.1007/s10930-007-9120-1.
Fourier-transform infrared spectroscopy, in vitro bioassay and enzyme-linked immunoassay were used to study the structural-functional relationships of recombinant mink growth hormone (mGH), refolded and stored under different conditions. Porcine GH (pGH) was synthesized and used as an example. These two hormones, when refolded and stored the same way, had the same secondary structures, biological and immunological efficacy, and biological potency. Only the immunological potency differed, mGH being significantly less potent than pGH. Renaturation pH and storing frozen or at 4 degrees C in 5% glycerol did not affect either the secondary structure or the activity. However, freeze-drying raised the content of buried alpha-helices and lowered that of solvated alpha-helices and of unordered structures. These conformational changes were associated with a reduction of immunological and biological potency of mGH and of immunological potency of pGH. These findings provide original information on the secondary structure of mGH, and show that conformational changes induced by lyophilization adversely affect its activity.
采用傅里叶变换红外光谱、体外生物测定和酶联免疫测定法，研究了在不同条件下复性和储存的重组水貂生长激素（mGH）的结构-功能关系。以合成的猪生长激素（pGH）为例。这两种激素以相同方式复性和储存时，具有相同的二级结构、生物学和免疫学效力以及生物活性。只是免疫学活性有所不同，mGH的效力明显低于pGH。复性pH值以及在5%甘油中冷冻或4℃储存均不影响二级结构或活性。然而，冻干增加了埋藏α-螺旋的含量，降低了溶剂化α-螺旋和无序结构的含量。这些构象变化与mGH的免疫学和生物学活性以及pGH的免疫学活性降低有关。这些发现提供了关于mGH二级结构的原始信息，并表明冻干诱导的构象变化对其活性产生不利影响。
