Phosphorylation of ovalbumin by dry-heating in the presence of pyrophosphate: effect on protein structure and some properties.
Phosphorylation of ovalbumin by dry-heating in the presence of pyrophosphate: effect on protein structure and some properties.
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DOI：
10.1021/jf047793j
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发表时间：
2005-05
影响因子：
6.1
通讯作者：
Can-Peng Li;Y. Hayashi;H. Shinohara;H. Ibrahim;Y. Sugimoto;Junichi Kurawaki;N. Matsudomi;T. Aoki-T.-Ao
中科院分区：
文献类型：
--
作者：
Can-Peng Li;Y. Hayashi;H. Shinohara;H. Ibrahim;Y. Sugimoto;Junichi Kurawaki;N. Matsudomi;T. Aoki-T.-Ao
在pH 4.0和85℃的焦磷酸盐存在下，用干热法将卵清蛋白(OVA)磷酸化1天和5天，并对磷酸化OVA的理化和结构性质进行了研究。经磷酸化处理后，PP-OVA的含磷量增加到1.01%，其凝胶迁移率也有所提高。虽然干热OVA的溶解度有所下降，但磷酸化对其影响较小。圆二色谱表明，用α-螺旋含量来衡量OVA分子中二级结构的变化是轻微的。通过磷酸化，增强了羟基和二硫键之间的交换反应，增加了OVA的表面疏水性。OVA的色氨酸荧光强度因磷酸化而减弱，提示OVA分子通过磷酸化发生构象变化。虽然差示扫描量热法分析表明，经磷酸化处理后，OVA的变性温度从78.3℃降至70.1℃，但在pH 7.0条件下，OVA对热诱导不溶的稳定性有所提高。结果表明，在焦磷酸盐存在下，通过干热形成的OVA熔融(部分展开)构象。
Ovalbumin (OVA) was phosphorylated by dry-heating in the presence of pyrophosphate at pH 4.0 and 85 degrees C for 1 and 5 days, and the physicochemical and structural properties of phosphorylated OVA were investigated. The phosphorus content of OVA increased to 1.01% by phosphorylation, and the electrophoretic mobility of PP-OVA also increased. Although the solubility of dry-heated OVA decreased, the decrease was slightly depressed by phosphorylation. The circular dichroism spectra showed that the change of the secondary structure in the OVA molecule, as measured by alpha-helix content, was mild by phosphorylation. The exchange reaction between the sulfhydryl and disulfide groups was enhanced and the surface hydrophobicity of OVA increased by phosphorylation. The tryptophan fluorescence intensity of OVA decreased by phosphorylation, suggesting that the conformational change occurred in the OVA molecule by phosphorylation. Although the differential scanning calorimetry thermograms of OVA showed a lowering of the denaturation temperature from 78.3 to 70.1 degrees C by phosphorylation, the stability of OVA against heat-induced insolubility at pH 7.0 was improved. The results indicated molten (partially unfolded) conformations of OVA formed by dry-heating in the presence of pyrophosphate.