2017 Annual Meeting
(626b) Systematic Redesigning of E. coli water Channel Porin, Ompf, for Desired Pore Size Using Iterative Protein Redesign and Optimization (IPRO) Suite
Authors
Pore sizes between 0.3 nm and 0.5 nm are key to several industrial and environmental separations such as methane/CO2 and salt/water, which is accessible to the less stable AQP1. We classified the IPRO designs into three broad classes based on the final pore geometry. A cork-screw (CSD) class of IPRO-suggested design (pore constriction ~0.236 nm by ~0.194 nm) shows alternately stacked bulky groups along the pore periphery, which when expressed, purified and immobilized on a porous support, exhibits high hydraulic permeability and not only completely rejects glycine (75 Da) but also shows ~70% salt (58 Da) rejection. Another type of mutant (with 25 Trp mutations) shows a highly hydrophobic pore (pore constriction ~0.33 nm by ~0.35 nm) that exhibits several folds higher hydraulic permeabilities than AQP1. Herein we propose a platform for designing precisely tuned sub-nm membrane transporters which will play a pivotal role both in performing energy-efficient water treatment and vesicle mediated highly-selective transport of antibiotics. Subsequent efforts will be directed towards systematic mutation of membrane-facing residues for the OmpF mutant series of proteins to tune interactions with various biomimetic membrane materials.
1. Pantazes RJ, Grisewood MJ, Li T, Gifford NP, Maranas CD. The Iterative Protein Redesign and Optimization (IPRO) suite of programs. J Comput Chem. 2015;36(4):251-63.