MPAD: A Database for Binding Affinity of Membrane Protein-protein Complexes and their Mutants.

Membrane protein complexes are crucial for a large variety of biological functions which are mainly dictated by their binding affinity. Due to the intricate nature of their structure, however, the binding affinity of membrane proteins is less explored compared to globular proteins. Mutations in these complexes affect their binding affinity, as well as impair critical functions, and may lead to diseases. Although experimental binding affinity data have expanded in the literature, they are dispersed and it is necessary to compile them into a reliable and comprehensive database. Hence, we developed MPAD (Membrane Protein complex binding Affinity Database), which contains experimental binding affinities of membrane protein-protein complexes and their mutants along with sequence, structure, and functional information, membrane-specific features, experimental conditions, as well as literature information. MPAD has an easy-to-use interface and options to build search queries, display, sort, download, and upload the data are among the other features available to users. This database can be used to understand the factors influencing the binding affinity in membrane proteins when compared to globular proteins as well as the impact of mutations on binding affinity, which may have potential applications to structure-based drug design. MPAD can be freely accessed at https://web.iitm.ac.in/bioinfo2/mpad.