Crystal Structure of the Michaelis Complex between Tissue-type Plasminogen Activator and Plasminogen Activators Inhibitor-1
Gong, L., Liu, M., Zeng, T., Shi, X., Yuan, C., Andreasen, P.A., Huang, M.(2015) J Biol Chem 290: 25795-25804
- PubMed: 26324706 
- DOI: https://doi.org/10.1074/jbc.M115.677567
- Primary Citation of Related Structures:  
5BRR - PubMed Abstract: 
Thrombosis is a leading cause of death worldwide. Recombinant tissue-type plasminogen activator (tPA) is the Food and Drug Administration-approved thrombolytic drug. tPA is rapidly inactivated by endogenous plasminogen activator inhibitor-1 (PAI-1). Engineering on tPA to reduce its inhibition by PAI-1 without compromising its thrombolytic effect is a continuous effort. Precise details, with atomic resolution, of the molecular interactions between tPA and PAI-1 remain unknown despite previous extensive studies. Here, we report the crystal structure of the tPA·PAI-1 Michaelis complex, which shows significant differences from the structure of its urokinase-type plasminogen activator analogue, the uPA·PAI-1 Michaelis complex. The PAI-1 reactive center loop adopts a unique kinked conformation. The structure provides detailed interactions between tPA 37- and 60-loops with PAI-1. On the tPA side, the S2 and S1β pockets open up to accommodate PAI-1. This study provides structural basis to understand the specificity of PAI-1 and to design newer generation of thrombolytic agents with reduced PAI-1 inactivation.
Organizational Affiliation: 
From the State Key Laboratory of Structural Chemistry and Danish-Chinese Centre for Proteases and Cancer, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, 350002 Fujian, China.