Radiation inactivation analysis of influenza virus reveals different target sizes for fusion, leakage, and neuraminidase activities

Journal Article · Tue Oct 07 04:00:00 EDT 1986 · Biochemistry; (United States)

DOI:https://doi.org/10.1021/bi00368a064· OSTI ID:6850477

Gibson, S; Jung, C Y; Takahashi, M; Lenard, J

The size of the functional units responsible for several activities carried out by the influenza virus envelope glycoproteins was determined by radiation inactivation analysis. Neuraminidase activity, which resides in the glycoprotein NA, was inactivated exponentially with an increasing radiation dose, yielding a target size of 94 +/- 5 kilodaltons (kDa), in reasonable agreement with that of the disulfide-bonded dimer (120 kDa). All the other activities studied are properties of the HA glycoprotein and were normalized to the known molecular weight of the neuraminidase dimer. Virus-induced fusion activity was measured by two phospholipid dilution assays: relief of energy transfer between N-(7-nitro-2,1,3-benzoxadiazol-4-yl)dipalmitoyl-L-alpha- phosphatidylethanolamine (N-NBD-PE) and N-(lissamine rhodamine B sulfonyl)-dioleoyl-L-alpha-phosphatidylethanolamine (N-Rh-PE) in target liposomes and relief of self-quenching of N-Rh-PE in target liposomes. Radiation inactivation of fusion activity proceeded exponentially with radiation dose, yielding normalized target sizes of 68 +/- 6 kDa by assay i and 70 +/- 4 kDa by assay ii. These values are close to the molecular weight of a single disulfide-bonded (HA1 + HA2) unit (75 kDa), the monomer of the HA trimer. A single monomer is thus inactivated by each radiation event, and each monomer (or some part of it) constitutes a minimal functional unit capable of mediating fusion. Virus-induced leakage of calcein from target liposomes and virus-induced leakage of hemoglobin from erythrocytes (hemolysis) both showed more complex inactivation behavior: a pronounced shoulder was present in both inactivation curves, followed by a steep drop in activity at higher radiation levels.

• Research Organization: Univ. of Medicine and Dentistry of New Jersey, Piscataway
• OSTI ID: 6850477
• Journal Information: Biochemistry; (United States), Journal Name: Biochemistry; (United States) Vol. 20; ISSN BICHA
• Country of Publication: United States
• Language: English

Related Subjects

560130* -- Radiation Effects on Microorganisms
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
BIOCHEMISTRY
BIOLOGICAL EFFECTS
BIOLOGICAL FUNCTIONS
BIOLOGICAL RADIATION EFFECTS
CARBOHYDRATES
CELL CONSTITUENTS
CHEMISTRY
DOSE-RESPONSE RELATIONSHIPS
DOSES
ENERGY TRANSFER
ENZYME ACTIVITY
ENZYMES
FUNCTIONS
GLUCOPROTEINS
GLYCOSYL HYDROLASES
HEMOLYSIS
HYDROLASES
INACTIVATION
IONIZING RADIATIONS
LIPOSOMES
LYSIS
MICROORGANISMS
MOLECULAR WEIGHT
O-GLYCOSYL HYDROLASES
ORGANIC COMPOUNDS
ORGANOIDS
PARASITES
PATHOLOGICAL CHANGES
PROTEINS
RADIATION DOSES
RADIATION EFFECTS
RADIATIONS
SACCHARIDES
VIRUSES