A Correlated Force−Optical Study on the Self-Assembly Behavior of Annexin V on Model Membranes: Effect of Dye Conjugation
journal contributionposted on 02.10.2008, 00:00 by Jason J. Han, Seung-Han Park, Doo Wan Boo
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We have examined the self-assembled membrane-bound aggregates of two annexin V (A5) dye conjugates and compared them to those from native A5. Native A5 and FITC-labeled A5 (A5−FITC) both formed discrete well-defined crystalline monolayer domains of p6 symmetry. However, A5−FITC also showed additional domains with a corrugated appearance not observed in native A5. In contrast, Cy3-labeled A5 (A5−Cy3) showed a mixture of crystalline monolayer and irregular multilayered domains, with the ratio of the two types varying significantly from sample to sample, and also required a much longer incubation time than native A5 and A5−FITC. When A5−FITC and A5−Cy3 were co-incubated on the same bilayer, well-defined crystalline monolayer domains containing both A5−FITC and A5−Cy3 were consistently observed at a much shorter incubation time than that of pure A5−Cy3 alone, indicating that A5−FITC facilitates the inclusion of A5−Cy3. These results suggest that dye labels can affect A5 2D self-assembly and crystal formation on membrane surfaces.