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：1990
卷号：87
期号：5
页码：1850-1854
DOI：10.1073/pnas.87.5.1850
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：We have used intensified video fluorescence microscopy and digital image processing to observe and quantitate influenza virus (A/PR8/34/H1N1) fusion to human erythrocyte membranes. Viruses labeled with the lipid probe octadecylrhodamine B (R18) were seen to undergo fluorescence dequenching and eventual disappearance after exposure to pH levels known to induce virus-cell membrane fusion. Quantitative intensity measurements of single individual particles were possible. From these fluorescence data it has been possible to calculate the fraction of R18 dye molecules transferred from the virus to the cell. The redistribution of the lipid probe upon fusion at pH 5.0 had a t1/2 of 46 s, longer than expected for a free-diffusion model. The R18 loss was approximately twice as fast at pH 5.0 as at pH 5.1. No obvious delay until the start of fluorescence dequenching was observed after the pH changes, suggesting that activation processes are faster than the time resolution, 1-5 s, of the current method.
