The orientational freedom of molecular probes. The orientation factor in intramolecular energy transfer.
The measurement of the efficiency of Förster long-range resonance energy transfer between donor (D) and acceptor (A) luminophores attached to the same macromolecular substrate can be used to estimate the D-A separation, R. If the D and A transition dipoles sample all orientations with respect to the substrate (the isotropic condition) in a time short compared with the transfer time (the dynamic averaging condition), the average orientation factor less than K2 greater than is 2/3. If the isotropic condition is not satisfied but the dynamic averaging condition is, upper and lower bounds for less than K2 greater than, and thus R, may be obtained from observed D and A depolarizations, and these limits may be further narrowed if the transfer depolarization is also known. This paper offers experimental protocols for obtaining this reorientational information and presents contour plots of less than K2 greater than min and less than K2 greater than max as functions of generally observable depolarizations. This permits an uncertainty to be assigned to the determined value of R. The details of the D and A reoreintational process need not be known, but the orientational distributions are assumed to have at least approximate axial symmetry with respect to a stationary substrate. Average depolarization factors are derived for various orientational distribution functions that demonstrate the effects of various mechanisms for reorientation of the luminophores. It is shown that in general the static averaging regime does not lend itself to determinations of R.
D004735:Energy Transfer; D005453:Fluorescence; D046911:Macromolecular Substances; D008433:Mathematics; D008968:Molecular Conformation
D046911:Macromolecular Substances
Biochemistry. 1977 Dec 13;16(25):5538-45
144521
Biochim Biophys Acta. 1975 Mar 13;382(2):125-41
164241
Biochemistry. 1977 Apr 19;16(8):1548-54
192266
Biochemistry. 1977 May 3;16(9):1890-6
192277
J Biol Chem. 1978 Jan 10;253(1):311-7
201623
Biochemistry. 1978 May 30;17(11):2163-8
27209
Biochemistry. 1978 Mar 21;17(6):987-93
305259
Proc Natl Acad Sci U S A. 1977 May;74(5):1932-6
325561
Biochemistry. 1977 Nov 29;16(24):5234-41
336083
Annu Rev Biochem. 1978;47:819-46
354506
Arch Biochem Biophys. 1977 Mar;179(2):469-76
557958
Biochemistry. 1978 Jun 13;17(12):2423-9
678521
Biochemistry. 1978 Nov 14;17(23):5064-70
718874
Biochemistry. 1976 May 18;15(10):2097-104
776217
Biochemistry. 1976 Jun 29;15(13):2888-93
779833
J Mol Biol. 1976 Sep 15;106(2):297-313
789892
Biochem Biophys Res Commun. 1977 Mar 7;75(1):149-55
851496
Biophys J. 1977 Dec;20(3):289-305
922121
Biochemistry. 1976 Nov 16;15(23):5017-23
1032992
Proc Natl Acad Sci U S A. 1975 May;72(5):1807-11
1057171
Proc Natl Acad Sci U S A. 1975 Dec;72(12):4764-8
1061067
Proc Natl Acad Sci U S A. 1976 Feb;73(2):271-3
1061130
Biochem Biophys Res Commun. 1975 Sep 16;66(2):763-8
1180935
Biophys Chem. 1976 Jan;4(1):65-78
1247651
Q Rev Biophys. 1976 Feb;9(1):21-33
1273255
Biochemistry. 1976 May 18;15(10):2105-13
1276126
Biochemistry. 1973 Jan 16;12(2):268-75
4683001
J Mol Biol. 1974 Apr 25;84(4):643-7
4840871
Biochemistry. 1972 Aug 1;11(16):3015-22
5041907
Biopolymers. 1971;10(8):1317-29
5094574
Proc Natl Acad Sci U S A. 1967 Aug;58(2):719-26
5233469
Proc Natl Acad Sci U S A. 1970 Nov;67(3):1383-9
5274465
Biochemistry. 1969 Oct;8(10):3908-15
5346376
Biochemistry. 1968 Feb;7(2):777-87
5644140
Biopolymers. 1968 Jun;6(6):809-16
5654614
Proc Natl Acad Sci U S A. 1971 Sep;68(9):2099-101
16591942
Proc Natl Acad Sci U S A. 1972 Aug;69(8):2273-7
16592008
Biochemistry. 1977 May 31;16(11):2319-24
577184