Pressure-Induced Protein Adsorption at Aqueous鈥揝olid Interfaces

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• 作者：Juny Koo ; Mirko Erlkamp ; Sebastian Grobelny ; Roland Steitz ; Claus Czeslik
• 刊名：Langmuir
• 出版年：2013
• 出版时间：June 25, 2013
• 年：2013
• 卷：29
• 期：25
• 页码：8025-8030
• 全文大小：313K
• 年卷期：v.29,no.25(June 25, 2013)
• ISSN：1520-5827

文摘

There seems to be a general relation between the standard Gibbs energy change of unfolding, 螖G掳_unf, of a protein and its affinity to aqueous鈥搒olid interfaces. So-called 鈥渉ard鈥?proteins (螖G掳_unf is large) are found to adsorb less strongly to such interfaces than 鈥渟oft鈥?proteins (螖G掳_unf is small). Here, we provide direct support for this rule by using high pressure to modulate the folding stability of a protein. We have performed high-pressure total internal reflection fluorescence (HP-TIRF) spectroscopy and high-pressure neutron reflectometry (HP-NR) to measure the degree of adsorption and the structure of lysozyme on planar solid surfaces as a function of pressure for the first time. By carrying out these experiments at hydrophilic and hydrophobic surfaces with varying concentrations of glycerol, we have found strong evidence that 螖G掳_unf has indeed a direct influence. At high pressures, there is a larger degree of lysozyme adsorption, probably because lysozyme becomes a 鈥渟oft鈥?protein under these conditions. The results of this study demonstrate that high pressure is a very useful tool to explore thermodynamics of protein-interface interactions.