![]() ![]() Importantly, both the diffusion coefficients and the fractions of these subpopulations were time-dependent. However, a quantitative analysis showed that at least two subpopulations were present differing widely in diffusion coefficients. In addition, a large fraction of the P4K molecules appeared to be mobile and to move over extended distances by diffusion. Thus, a fraction of P4K molecules appeared to be truly immobile while another fraction was mobile but confined to very small areas. The present study supported this observation but revealed a much larger variety of mobility classes. Our previous photobleaching measurements indicated that P4K had two fractions inside the nucleus, a larger mobile and a smaller immobile fraction. Using the recombinant Escherichia coli β-galactosidase protein P4K, labeled with an average of 4.6 ALEXA 488 chromophores per tetramer, single P4K molecules could be localized and tracked in the nuclei of permeabilized 3T3 cells at a spatial accuracy of ∼30 nm and a time resolution of 18 ms. A recently developed laser fluorescence videomicroscopy method was used to determine for the first time the intranuclear trajectories of single protein molecules. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |