The Hydrogen-Bonding Network of Water Molecules and the Peptide Backbone in the Region Connecting Asp83, Gly120, and Glu113 in Bovine Rhodopsin

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• 作者：Tomoko Nagata ; Akihisa Terakita ; Hideki Kandori ; Yoshinori Shichida ; and Akio Maeda
• 刊名：Biochemistry
• 出版年：1998
• 出版时间：December 8, 1998
• 年：1998
• 卷：37
• 期：49
• 页码：17216 - 17222
• 全文大小：94K
• 年卷期：v.37,no.49(December 8, 1998)
• ISSN：1520-4995

文摘

Difference Fourier transform infrared spectra were recorded between mutants of rhodopsinand their batho products. The pigments studied were single and combined mutants of intramembraneresidues of bovine rhodopsin: Asp83, Glu113, Gly120, Gly121, and Glu122. Previous studies [Nagata,T., Terakita, A., Kandori, H., Kojima, D., Shichida, Y., and Maeda, A. (1997) Biochemistry 36, 6164-6170] showed that one of the water molecules which undergoes structural changes in this process formshydrogen bonds with Glu113 and the Schiff base, and that another water molecule is linked to this structurethrough the peptide backbone. The present results show that this water molecule is located at the placethat is affected by the replacements of Asp83 and Gly120 but only slightly by Gly121 and not at all byGlu122. Asp83 and Gly120 are close to each other, in view of the observations that the carboxylic C=Ostretching vibration of Asp83 is affected by the G120A replacement and that each replacement affects thecommon peptide carbonyl groups. Our results suggest that these residues in the middle of helices B andC are linked-through a hydrogen-bonding network composed of water and the peptide backbone-withthe region around Glu113.