作者:Viktor Farkas、Elemér Vass、Ignace Hanssens、Zsuzsa Majer、Miklós Hollósi
DOI:10.1016/j.bmc.2005.06.040
日期:2005.9
coordinating the cation. The structural features of synthetic peptides and their Ca2+-binding properties were investigated in solution by circular dichroism (CD) and Fourier transform infrared (FTIR) spectroscopy. In water, the CD curves show a strong negative band below 200 nm as a sign of the presence of unfolded conformers. In TFE, all cyclic peptides were found to have a CD spectrum, reflecting the
设计并合成了一系列具有不同接头的环状肽,以模拟α-乳清蛋白(LA)的肘型Ca2 +结合环。Ca2 +结合环的所有氨基酸在不同物种的LA之间都具有非常好的保守性,序列为Lys79-Phe-Leu-Asp82-Asp-Asp-Leu-Thr-Asp87-Asp88,其中Asp82,Asp87和Asp88和Lys79和Asp84的酰胺羰基氧原子参与Ca2 +的结合。还制备了含丙氨酸的模型以监测结合(82、87-88)和非结合Asp残基(83-84)在协调阳离子中的作用。通过溶液的圆二色性(CD)和傅立叶变换红外光谱(FTIR)研究了合成肽的结构特征及其与Ca 2+的结合特性。在水里,CD曲线显示在200 nm以下有很强的负带,表明存在未折叠构象异构体。在TFE中,发现所有环状肽均具有CD光谱,反映了折叠(转向)构象体的存在。Ca2 +的作用取决于模型的结构和浓度以及Ca2 +与肽的比率(r(cat))。观察到了含Ala肽的Ca2