title: Fluorescence and flow dichroism of F-actin-epsilon-ADP; the orientation of the admine plane relative to the long axis of F-actin.
abstract: The excitation polarization spectrum of epsilon-ADP bound to F-actin shows that two absorption dipoles at 260 nm and 340 nm are oriented in different directions relative to the emission dipole. On the other hand, the linear dichroism of F-actin-epsilon-ADP gives that the dichroic ratio of the bound epsilon-ADP is approximately constant (about-0.5) in the wavelength region form 250 to 350nm. Furthermore, the fluorescence polarization of epsilon-ADP bound to F-actin which is oriented in the field of flow shows that the emission dipole is nearly perpendicular to the long axis of F-actin. From these observations we conclude that the adenine plane of the bound nucleotide is almost perpendicular to the long axis of F-actin.
mesh_terms: D000199:Actins; D000225:Adenine; D000244:Adenosine Diphosphate; D000818:Animals; D001665:Binding Sites; D002942:Circular Dichroism; D046911:Macromolecular Substances; D008433:Mathematics; D009132:Muscles; D011485:Protein Binding; D011487:Protein Conformation; D011817:Rabbits; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet
chemical_list: D000199:Actins; D046911:Macromolecular Substances; D000244:Adenosine Diphosphate; D000225:Adenine