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:1979
卷号:76
期号:11
页码:5843-5847
DOI:10.1073/pnas.76.11.5843
语种:English
出版社:The National Academy of Sciences of the United States of America
摘要:We have compared the effects of the complement membrane attack complex (MAC), nystatin, and melittin on the envelope of murine leukemia viruses to determine if channel formation alone is sufficient to cause membranolysis. Nystatin is a channel former and mellitin is not, although both are hemolytic. Whereas MAC and melittin disintegrated the viral membrane, nystatin had no effect on morphology, integrity, and infectivity of the virus. Incorporation of the antibiotic into the viral membranes was demonstrated by measurements of the characteristic fluorescence of nystatin in membranes and the dose-dependent increase in viral density after uptake of the antibiotic. The density of nystatin was measured to be 1.26-1.27 g/cm3. Proof for the formation of functional nystatin channels was obtained by light scattering measurements. Exposure of untreated virus to hypotonic conditions increased viral light scattering because of osmotic swelling but otherwise had no effect on the integrity of the virus. Nystatin channel formation abolished the light scattering change, showing that the antibiotic had impaired the viral permeability barrier. We interpret these results to indicate that virolysis by MAC is not caused by channel formation and, conversely, in the absence of colloid-osmotic effects, channel formation by itself is not sufficient to disassemble a viral membrane.