La Crosse virus G1 glycoprotein undergoes a conformational change at the pH of fusion.

La Crosse virus, a member of the family Bunyaviridae, can mediate cell-to-cell fusion after mild acidification. Either of its two envelope glycoproteins could potentially be responsible for this function. The large glycoprotein (G1) undergoes a conformational change at the pH of activation of the fusion function, resulting in both an alteration in the cleavage pattern produced by amino-acid-specific proteases, and in a change in its antigenicity, as defined by altered binding of monoclonal antibodies.