Chemical studies of viral entry mechanisms: I. Hydrophobic protein-lipid interactions during Sendai virus membrane fusion. II. Kinetics of bacteriophage. lambda. DNA injection

Thesis/Dissertation · Mon Jan 01 04:00:00 EST 1990

OSTI ID:6322404

Novick, S L

Sendai virus glycoprotein interactions with target membranes during the early stages of fusion were examined using time-resolved hydrophobic photoaffinity labeling with the lipid-soluble carbene generator 3-(trifluoromethyl)-3-(m({sup 125}I) iodophenyl)diazirine. During Sendai virus fusion with liposomes composed of cardiolipin or phosphatidylserine, the viral fusion (F) protein is preferentially labeled at early time points, supporting the hypothesis that hydrophobic interaction of the fusion peptide at the N-terminus of the F{sub 1} subunit with the target membrane is an initiating event in fusion. Correlation of hydrophobic interactions with independently monitored fusion kinetics further supports this conclusion. The F{sub 1} subunit, containing the putative hydrophobic fusion sequence, is exclusively labeled, and the F{sub 2} subunit does not participate in fusion. Labeling shows temperature and pH dependence consistent with a need for protein conformational mobility and fusion at neutral pH. Higher amounts of labeling during fusion with CL vesicles than during virus-PS vesicle fusion reflects membrane packing regulation of peptide insertion into target membranes. Labeling of the viral hemagglutinin/neuraminidase (HN) at low pH indicates that HN-mediated fusion is triggered by hydrophobic interactions. Controls for diffusional labeling exclude a major contribution from this source. Labeling during reconstituted Sendai virus envelope-liposome fusion shows that functional reconstitution involves protein retention of the ability to undergo hydrophobic interactions. Examination of Sendai virus fusion with erythrocyte membranes indicates that hydrophobic interactions also trigger fusion between biological membranes. The data show that hydrophobic fusion protein interaction with both artificial and biological membranes is a triggering event in fusion.

• Research Organization: California Inst. of Tech., Pasadena, CA (USA)
• OSTI ID: 6322404
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
550901 -- Pathology-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
BACTERIOPHAGES
BETA DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BODY FLUIDS
CELL CONSTITUENTS
CELL MEMBRANES
DAYS LIVING RADIOISOTOPES
DISEASES
DNA
ELECTRON CAPTURE RADIOISOTOPES
ERYTHROCYTES
GLYCOPROTEINS
INFECTIOUS DISEASES
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
LABELLING
MATERIALS
MEMBRANES
MICROORGANISMS
NUCLEI
NUCLEIC ACIDS
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
PARASITES
PATHOGENESIS
PROTEINS
RADIOISOTOPES
REACTION KINETICS
TEMPERATURE DEPENDENCE
TRACER TECHNIQUES
VIRAL DISEASES
VIRUSES