|
|
||||||||
Section of Membrane Structure and Function, National Cancer Institute, National Institutes of Health, Building 10, Room 4A01, 9000 Rockville Pike, Bethesda, Maryland 20892, U.S.A.
The fusion kinetics with erythrocyte ghosts of two influenza A virus strains, A/Aichi/2/68 (X:31) and A/PR/8/34 (PR/8), were compared and correlated with the kinetics of haemagglutinin (HA) conformational change. Previously it had been shown that X:31 fuses with liposomes or erythrocytes at 4 °C, pH 5 after a lag time of 5 to 10 min whereas PR/8 displayed no fusion with liposomes at that temperature. We have confirmed the absence of cold fusion by PR/8 with erythrocyte ghosts. In contrast to X:31, PR/8 could not be committed to fuse at neutral pH and 37 °C by a preincubation at low pH and 4 °C. To examine whether the lack of commitment and cold fusion were due to a failure of PR/8 HA to undergo conformational changes at low temperature and pH, we analysed susceptibility of HA to proteinase K digestion, liposome binding to the virus, and immunoprecipitations of HA with conformation-specific antibodies. Although there was little binding of PR/8 to liposomes at 4 °C and pH 5, we did observe exposure of the fusion peptide. This study reveals a low temperature intermediate in membrane fusion exhibited by the HA of influenza virus strain PR/8, which involves low pH-induced conformational changes including exposure of the fusion peptide with little interaction of HA with the target membrane.
Received 5 July 1993;
accepted 17 September 1993.
This article has been cited by other articles:
![]() |
M. A. Zhukovsky, E. Leikina, I. Markovic, A. L. Bailey, and L. V. Chernomordik Heterogeneity of Early Intermediates in Cell-Liposome Fusion Mediated by Influenza Hemagglutinin Biophys. J., November 1, 2006; 91(9): 3349 - 3358. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. J. Edwards and N. J. Dimmock Hemagglutinin 1-Specific Immunoglobulin G and Fab Molecules Mediate Postattachment Neutralization of Influenza A Virus by Inhibition of an Early Fusion Event J. Virol., November 1, 2001; 75(21): 10208 - 10218. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. Korte, K. Ludwig, F. P. Booy, R. Blumenthal, and A. Herrmann Conformational Intermediates and Fusion Activity of Influenza Virus Hemagglutinin J. Virol., June 1, 1999; 73(6): 4567 - 4574. [Abstract] [Full Text] |
||||
![]() |
C. Cianci, K.-L. Yu, D. D. Dischino, W. Harte, M. Deshpande, G. Luo, R. J. Colonno, N. A. Meanwell, and M. Krystal pH-Dependent Changes in Photoaffinity Labeling Patterns of the H1 Influenza Virus Hemagglutinin by Using an Inhibitor of Viral Fusion J. Virol., March 1, 1999; 73(3): 1785 - 1794. [Abstract] [Full Text] |
||||
![]() |
L. V. Chernomordik, V. A. Frolov, E. Leikina, P. Bronk, and J. Zimmerberg The Pathway of Membrane Fusion Catalyzed by Influenza Hemagglutinin: Restriction of Lipids, Hemifusion, and Lipidic Fusion Pore Formation J. Cell Biol., March 23, 1998; 140(6): 1369 - 1382. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| INT J SYST EVOL MICROBIOL | MICROBIOLOGY | J GEN VIROL |
| J MED MICROBIOL | ALL SGM JOURNALS | |