Interaction of influenza M protein with viral lipid and phosphatidylcholine vesicles.
The M protein of influenza is the predominant structural component of the virus. The interactions of this protein with the viral lipid or with other proteins are not known. The ability of M to interact with viral or other lipids was investigated. Purified M was mixed with viral lipid or egg phosphatidylcholine and was incorporated into vesicles (i) by addition of sodium deoxycholate followed by dialysis or (ii) by sonication. Between 90 and 100% of the M became firmly associated with the lipid by either of these two methods, whereas nucleoprotein failed to associate with the vesicles. From association also occurred if M was mixed with performed vesicles. Most of the M attached to the vesicles could be hydrolyzed with proteolytic enzymes such as trypsin or thermolysin, except for a small fragment of about 5,000 daltons which remained associated with the lipid vesicles. The ability of fragments of M to interact with lipids was also investigated. Of 13 fragments produced by cleavage with cyanogen bromide, 3 specifically associated with lipid vesicles. The data indicate that a specific portion of the M molecule has a high affinity for lipid bilayers of various origins.
D000596:Amino Acids / Q000032:analysis; D055598:Chemical Phenomena; D002621:Chemistry; D009980:Influenza A virus / Q000032:analysis*; D008055:Lipids; D008081:Liposomes; D010713:Phosphatidylcholines; D013820:Thermolysin / Q000494:pharmacology; D014357:Trypsin / Q000494:pharmacology; D014764:Viral Proteins
D000596:Amino Acids; D008055:Lipids; D008081:Liposomes; D010713:Phosphatidylcholines; D014764:Viral Proteins; D014357:Trypsin; D013820:Thermolysin