Aggregates with lysozyme and ovalbumin show features of amyloid-like fibrils.
Aggregates with lysozyme and ovalbumin show features of amyloid-like fibrils.
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DOI：
10.1139/o11-041
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发表时间：
2011-10
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影响因子：
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通讯作者：
Y. Sugimoto;Yoshiki Kamada;Yuhei Tokunaga;H. Shinohara;M. Matsumoto;T. Kusakabe;T. Ohkuri;T. Ueda
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文献类型：
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作者：
Y. Sugimoto;Yoshiki Kamada;Yuhei Tokunaga;H. Shinohara;M. Matsumoto;T. Kusakabe;T. Ohkuri;T. Ueda
以溶菌酶溶菌酶溶菌酶活性抑制、差示扫描量热法和圆二色谱法为指标，研究了蛋清溶菌酶与变性温度为78 °C的N-卵清蛋白的相互作用。当溶菌酶和N-卵白蛋白的混合物在72 °C下共加热时，相互作用的信号最显著，略低于N-卵白蛋白的T（m）。当未加热的溶菌酶与在72 °C预热的N-卵清蛋白混合时，这种相互作用也很明显。此外，该混合物迅速形成纤维状沉淀物，其对硫磺素T荧光发射呈阳性，硫磺素T荧光发射是淀粉样蛋白原纤维形成的标志物。电子显微镜观察也显示出纤维的特征。卵清蛋白的相互作用效力归因于胰蛋白酶片段ILELPFASGT MSMLVLLPDE VSGLEQLESIINFEK（残基229-263），其来源于卵清蛋白的2B链2和3。另一方面，来自溶菌酶的胰凝乳蛋白酶肽RNRCKGTDVQAW（残基112-123）（包括簇6）和胰凝乳蛋白酶/胰蛋白酶肽GILQINSRW（残基54-62）（包括簇3）负责与N-卵白蛋白的相互作用。有趣的是，发现这种九聚体肽具有自聚集的能力。据作者所知，这可能是第一份报告，以文件的双重蛋白质可能参与淀粉样纤维的形成。
The interaction of egg-white lysozyme with N-ovalbumin, the native form of egg-white ovalbumin with the denaturation temperature, T(m), of 78 °C, was investigated by the inhibition of lysozyme muramidase activity, differential scanning calorimetry, and circular dichroism assay as indicators. Signals for the interaction were the most prominent when the mixture of lysozyme and N-ovalbumin was co-heated at 72 °C, slightly lower than the T(m) of N-ovalbumin. The interaction was also marked when unheated lysozyme was mixed with N-ovalbumin preheated at 72 °C. Moreover, the mixture rapidly formed fibrous precipitates, which were positive for thioflavin T fluorescent emission, a marker for the amyloid fibril formation. Also electron microscopic observation exhibited features of fibrils. The interaction potency of ovalbumin was ascribed to the tryptic fragment ILELPFASGT MSMLVLLPDE VSGLEQLESIINFEK (residues 229-263), derived from the 2B strands 2 and 3 of ovalbumin. From lysozyme, on the other hand, the chymotryptic peptide RNRCKGTDVQAW (residues 112-123), including cluster 6, and the chymotryptic/tryptic peptide GILQINSRW (residues 54-62), including cluster 3, were responsible for the interaction with N-ovalbumin. Interestingly, this nonamer peptide was found to have the ability to self-aggregate. To the authors knowledge, this may be the first report to document the possible involvement of dual proteins in the formation of amyloid-like fibrils.