Folding of PAI-1 Protein (IMAGE) University of Southern Denmark Caption The red and blue ribbons show how the protein PAI-1 unfolds right before it destroys itself. On the last picture the protein's active site (green dotted line) has been inactivated (turned into a wide green line), indicating that now the protein is off. It cannot be activated again, but will be removed from the blood as garbage, and new PAI-1 proteins will be produced. Credit University of Southern Denmark 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.