Hydrophobic residues in S1 modulate enzymatic function and voltage sensing in voltage-sensing phosphatase.

ABSTRACT: The voltage-sensing domain (VSD) is a four-helix modular protein domain that converts electrical signals into conformational changes, leading to open pores and active enzymes. In most voltage-sensing proteins, the VSDs do not interact with one another, and the S1-S3 helices are considered mainly scaffolding, except in the voltage-sensing phosphatase (VSP) and the proton channel (Hv). To investigate its contribution to VSP function, we mutated four hydrophobic amino acids in S1 to alanine (F127, I131, I134, and L137), individually or in combination. Most of these mutations shifted the voltage dependence of activity to higher voltages; however, not all substrate reactions were the same. The kinetics of enzymatic activity were also altered, with some mutations significantly slowing down depho

SUBMITTER: Rayaprolu V 

PROVIDER: S-EPMC11109755 | biostudies-literature | 2024 Jul

REPOSITORIES: biostudies-literature