Conformational Stability of the Potato Serine Protease Inhibitor Group

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• 作者：Laurice Pouvreau ; Harry Gruppen ; Gerrit van Koningsveld ; Lambertus A. M. van den Broek ; and Alhons G. J. Voragen
• 刊名：Journal of Agricultural and Food Chemistry
• 出版年：2005
• 出版时间：April 20, 2005
• 年：2005
• 卷：53
• 期：8
• 页码：3191 - 3196
• 全文大小：148K
• 年卷期：v.53,no.8(April 20, 2005)
• ISSN：1520-5118

文摘

The thermal unfolding of potato serine protease inhibitor (PSPI), the most abundant protease inhibitorgroup in potato tuber, was measured using far UV CD spectroscopy, fluorescence spectroscopy,and DSC. The results indicate that the thermal as well as the guanidinium-induced unfolding of PSPIoccurs via a non-two-state mechanism in which at least one stable intermediate is present. Additionally,the occurrence of aggregation, especially at low scan rates, increases the apparent cooperativity ofthe unfolding and makes the system kinetically rather than thermodynamically controlled. Aggregateformation seems to occur via a specific mechanism of which PSPI in a tetrameric form is the endproduct and which may involve disulfide interchanges.Keywords: PSPI; aggregation; equilibrium