Structural and Energetic Basis of Carbohydrate鈥揂romatic Packing Interactions in Proteins

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• 作者：Wentao Chen ; Sebastian Enck ; Joshua L. Price ; David L. Powers ; Evan T. Powers ; Chi-Huey Wong ; H. Jane Dyson ; Jeffery W. Kelly
• 刊名：The Journal of the American Chemical Society
• 出版年：2013
• 出版时间：July 3, 2013
• 年：2013
• 卷：135
• 期：26
• 页码：9877-9884
• 全文大小：553K
• 年卷期：v.135,no.26(July 3, 2013)
• ISSN：1520-5126

文摘

Carbohydrate鈥揳romatic interactions mediate many biological processes. However, the structure鈥揺nergy relationships underpinning direct carbohydrate鈥揳romatic packing interactions in aqueous solution have been difficult to assess experimentally and remain elusive. Here, we determine the structures and folding energetics of chemically synthesized glycoproteins to quantify the contributions of the hydrophobic effect and CH鈭捪€ interactions to carbohydrate鈥揳romatic packing interactions in proteins. We find that the hydrophobic effect contributes significantly to protein鈥揷arbohydrate interactions. Interactions between carbohydrates and aromatic amino acid side chains, however, are supplemented by CH鈭捪€ interactions. The strengths of experimentally determined carbohydrate CH鈭捪€ interactions do not correlate with the electrostatic properties of the involved aromatic residues, suggesting that the electrostatic component of CH鈭捪€ interactions in aqueous solution is small. Thus, tight binding of carbohydrates and aromatic residues is driven by the hydrophobic effect and CH鈭捪€ interactions featuring a dominating dispersive component.