- gp160, the envelope glycoprotein of human immunodeficiency virus type 1, is a dimer of 125-kilodalton subunits stabilized through interactions between their gp41 domains. Thomas, D.J., Wall, J.S., Hainfeld, J.F., Kaczorek, M., Booy, F.P., Trus, B.L., Eiserling, F.A., Steven, A.C. J. Virol. (1991)