MPA-Pred: A machine learning approach for predicting the binding affinity of membrane protein-protein complexes.

Membrane protein-protein interactions are essential for several functions including cell signaling, ion transport, and enzymatic activity. These interactions are mainly dictated by their binding affinities. Although several methods are available for predicting the binding affinity of protein-protein complexes, there exists no specific method for membrane protein-protein complexes. In this work, we collected the experimental binding affinity data for a set of 114 membrane protein-protein complexes and derived several structure and sequence-based features. Our analysis on the relationship between binding affinity and the features revealed that the important factors mainly depend on the type of membrane protein and the functional class of the protein. Specifically, aromatic and charged residues at the interface, and aromatic-aromatic and electrostatic interactions are found to be important to understand the binding affinity. Further, we developed a method, MPA-Pred, for predicting the binding affinity of membrane protein-protein complexes using a machine learning approach. It showed an average correlation and mean absolute error of 0.83 and 0.91 kcal/mol, respectively, using the jack-knife test on a set of 114 complexes. We have also developed a web server and it is available at https://web.iitm.ac.in/bioinfo2/MPA-Pred/. This method can be used for predicting the affinity of membrane protein-protein complexes at a large scale and aid to improve drug design strategies.

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.

Computational Approaches for Investigating Disease-causing Mutations in Membrane Proteins: Database Development, Analysis and Prediction.

Membrane proteins (MPs) play an essential role in a broad range of cellular functions, serving as transporters, enzymes, receptors, and communicators, and about ~60% of membrane proteins are primarily used as drug targets. These proteins adopt either α-helical or ß-barrel structures in the lipid bilayer of a cell/organelle membrane. Mutations in membrane proteins alter their structure and function, and may lead to diseases. Data on disease-causing and neutral mutations in membrane proteins are available in MutHTP and TMSNP databases, which provide additional features based on sequence, structure, topology, and diseases. These databases have been effectively utilized for analysing sequence and structure-based features in disease-causing and neutral mutations in membrane proteins, exploring disease-causing mechanisms, elucidating the relationship between sequence/structural parameters and diseases, and developing computational tools. Further, machine learning-based tools have been developed for identifying disease-causing mutations using diverse features, such as evolutionary information, physicochemical properties, atomic contacts, contact potentials, and the contribution of different energetic terms. These membrane protein-specific tools are helpful in characterizing the effect of new variants in the whole human membrane proteome. In this review, we provide a discussion of the available databases for disease-causing mutations in membrane proteins, followed by a statistical analysis of membrane protein mutations using sequence and structural features. In addition, available prediction tools for identifying disease-causing and neutral mutations in membrane proteins will be described with their performances. This comprehensive review provides deep insights into designing mutation-specific strategies for different diseases.

Ab-CoV: a curated database for binding affinity and neutralization profiles of coronavirus-related antibodies.

SUMMARY: We have developed a database, Ab-CoV, which contains manually curated experimental interaction profiles of 1780 coronavirus-related neutralizing antibodies. It contains more than 3200 datapoints on half maximal inhibitory concentration (IC50), half maximal effective concentration (EC50) and binding affinity (KD). Each data with experimentally known three-dimensional structures are complemented with predicted change in stability and affinity of all possible point mutations of interface residues. Ab-CoV also includes information on epitopes and paratopes, structural features of viral proteins, sequentially similar therapeutic antibodies and Collier de Perles plots. It has the feasibility for structure visualization and options to search, display and download the data. AVAILABILITY AND IMPLEMENTATION: Ab-CoV database is freely available at https://web.iitm.ac.in/bioinfo2/ab-cov/home. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.