HIV-1 Envelope Protein (IMAGE) University of Zurich Caption An antibody (dark grey) is binding to an HIV envelope protein (coloured) on the surface of the virus (light grey). Credit University of Zurich Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.