title: Affinity thresholds for membrane fusion triggering by viral glycoproteins.
abstract: Enveloped viruses trigger membrane fusion to gain entry into cells. The receptor affinities of their attachment proteins vary greatly, from 10(-4) M to 10(-9) M, but the significance of this is unknown. Using six retargeted measles viruses that bind to Her-2/neu with a 5-log range in affinity, we show that receptor affinity has little impact on viral attachment but is nevertheless a key determinant of infectivity and intercellular fusion. For a given cell surface receptor density, there is an affinity threshold above which cell-cell fusion proceeds efficiently. Suprathreshold affinities do not further enhance the efficiency of membrane fusion.
authors.affiliation: Molecular Medicine Program, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA.
authors.forename: Kosei
authors.initials: K
authors.lastname: Hasegawa
authors.forename: Chunling
authors.initials: C
authors.lastname: Hu
authors.forename: Takafumi
authors.initials: T
authors.lastname: Nakamura
authors.forename: James D
authors.initials: JD
authors.lastname: Marks
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Russell
authors.forename: Kah-Whye
authors.initials: KW
authors.lastname: Peng
mesh_terms: D000818:Animals; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D006023:Glycoproteins / Q000378:metabolism*; D006801:Humans; D008459:Measles virus / Q000502:physiology; D008561:Membrane Fusion; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D011991:Receptors, Virus / Q000378:metabolism*; D014759:Viral Envelope Proteins / Q000378:metabolism*; D053585:Virus Attachment; D053586:Virus Internalization; D018406:Virus Physiological Phenomena