Biomaterial Database

Reversible pH-dependent conformational change of reconstituted influenza hemagglutinin. 1996

S A Tatulian, and L K Tamm

Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Charlottesville, VA 22908, USA.

Fusion between influenza virus and cell membranes is mediated by a major acid-induced conformational change of the spike glycoprotein of the viral envelope, hemagglutinin (HA). The conformational change of HA is commonly believed to be a kinetically controlled irreversible process, although the experimental evidence for this is controversial. Here we show by polarized infrared spectroscopy that the previously described acid-induced inclination of HA reconstituted in supported phospholipid bilayers is reversible in the absence, but irreversible in the presence, of bound target membranes. We also demonstrate reversible pH-dependent changes in the capability of reconstituted HA to bind target membranes. These results support a thermodynamically controlled mechanism of the conformational change of HA and provide new insight into the understanding of the energetics of influenza-mediated membrane fusion.

UI	MeSH Term	Description	Entries
D009975	Orthomyxoviridae	A family of RNA viruses causing INFLUENZA and other respiratory diseases. Orthomyxoviridae includes INFLUENZAVIRUS A; INFLUENZAVIRUS B; INFLUENZAVIRUS C; INFLUENZAVIRUS D; ISAVIRUS; and THOGOTOVIRUS.	Influenza Viruses,Myxoviruses,Orthomyxoviruses,Influenza Virus,Myxovirus,Orthomyxovirus
D011487	Protein Conformation	The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).	Conformation, Protein,Conformations, Protein,Protein Conformations
D006389	Hemagglutinins, Viral	Specific hemagglutinin subtypes encoded by VIRUSES.	Viral Hemagglutinin,Viral Hemagglutinins,Hemagglutinin, Viral
D006863	Hydrogen-Ion Concentration	The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH	pH,Concentration, Hydrogen-Ion,Concentrations, Hydrogen-Ion,Hydrogen Ion Concentration,Hydrogen-Ion Concentrations
D017550	Spectroscopy, Fourier Transform Infrared	A spectroscopic technique in which a range of wavelengths is presented simultaneously with an interferometer and the spectrum is mathematically derived from the pattern thus obtained.	FTIR,Fourier Transform Infrared Spectroscopy,Spectroscopy, Infrared, Fourier Transform
D019267	Hemagglutinin Glycoproteins, Influenza Virus	Membrane glycoproteins from influenza viruses which are involved in hemagglutination, virus attachment, and envelope fusion. Fourteen distinct subtypes of HA glycoproteins and nine of NA glycoproteins have been identified from INFLUENZA A VIRUS; no subtypes have been identified for Influenza B or Influenza C viruses.