Hydrophobic photolabeling identifies BHA2 as the subunit mediating the interaction of bromelain-solubilized influenza virus hemagglutinin with liposomes at low pH

Journal Article · Tue Mar 22 04:00:00 EST 1988 · Biochemistry; (United States)

DOI:https://doi.org/10.1021/bi00406a010· OSTI ID:6908812

Harter, C; Baechi, T S; Semenza, G; Brunner, J

To investigate the molecular basis of the low-pH-mediated interaction of the bromelain-solubilized ectodomain of influenza virus hemagglutinin (BHA) with membranes, we have photolabeled BHA in the presence of liposomes with the two carbene-generating, membrane-directed reagents 3-(trifluoromethyl)-3-(m-(/sup 125/I)iodophenyl)diazirine ((/sup 125/I)TID) and a new analogue of a phospholipid, 1-palmitoyl-2-(11-(4-(3-(trifluoromethyl)diazirinyl)phenyl)(2-/sup 3/H) undecanoyl)-sn-glycero-3-phosphocholine ((/sup 3/H)-PTPC/11). With the latter reagent, BHA was labeled in a strictly pH-dependent manner, i.e., at pH 5 only, whereas with (/sup 125/I)TID, labeling was seen also at pH 7. In all experiments, the label was selectively incorporated into the BHA2 polypeptide, demonstrating that the interaction of BHA with membranes is mediated through this subunit, possibly via its hydrophobic N-terminal segment. Similar experiments with a number of other water-soluble proteins (ovalbumin, carbonic anhydrase, alpha-lactalbumin, trypsin, and soybean trypsin inhibitor) indicate that the ability to interact with liposomes at low pH is not a property specific for BHA but is observed with other, perhaps most, proteins.

• Research Organization: Laboratorium fuer Biochemie der Eidgenoessischen Technischen Hochschule, Zuerich (Switzerland)
• OSTI ID: 6908812
• Journal Information: Biochemistry; (United States), Journal Name: Biochemistry; (United States) Vol. 27:6; ISSN BICHA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AGGLUTININS
ANTIBODIES
BETA DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
CELL CONSTITUENTS
CELL MEMBRANES
DAYS LIVING RADIOISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
HEMAGGLUTININS
INFLUENZA VIRUSES
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
LABELLED COMPOUNDS
LABELLING
LIPOSOMES
MAGNETIC RESONANCE
MEMBRANES
MICROORGANISMS
MOLECULAR BIOLOGY
NUCLEAR MAGNETIC RESONANCE
NUCLEI
ODD-EVEN NUCLEI
ORGANOIDS
PARASITES
PH VALUE
RADIOISOTOPES
REACTION KINETICS
REAGENTS
RESONANCE
SOLUBILITY
TRACER TECHNIQUES
TRITIUM COMPOUNDS
VIRUSES