期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1978
卷号：75
期号：8
页码：3669-3672
DOI：10.1073/pnas.75.8.3669
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Fluorescence techniques were used to study conformational changes in UDPgalactose:lipopolysaccharide alpha,3-galactosyltransferase (EC 2.4.1.44 ). Intramolecular energy transfer was measured from the single tryptophan residue in the peptide to a pyridoxal phosphate group linked to the same peptide via a reduced Schiff's base. Significant differences in energy transfer were seen when the enzyme was studied in aqueous solution and after entry into a phospholipid-lipopolysaccharide matrix, paralleling the restoration of its catalytic activity. Further differences were seen when the structures of the phospholipids and lipopolysaccharides were changed. Application of the Forster theory indicated that the changes in energy transfer resulted from changes in distances between the chromophores and/or changes in their relative orientations. The results suggest that entry of this membrane protein into a lipid matrix induces a change in conformation of the protein and that other alternative conformations can be induced by further changes in its lipid environment.
