The Highly Conservative Cysteine of Oncomodulin as a Feasible Redox Sensor.

ABSTRACT: Oncomodulin (Ocm), or parvalbumin β, is an 11-12 kDa Ca²⁺-binding protein found inside and outside of vertebrate cells, which regulates numerous processes via poorly understood mechanisms. Ocm consists of two active Ca²⁺-specific domains of the EF-hand type ("helix-loop-helix" motif), covered by an EF-hand domain with inactive EF-hand loop, which contains a highly conservative cysteine with unknown function. In this study, we have explored peculiarities of the microenvironment of the conservative Cys18 of recombinant rat Ocm (rWT Ocm), redox properties of this residue, and structural/functional sensitivity of rWT Ocm to the homologous C18S substitution. We have found that pK_a of the Cys18 thiol lays beyond the physiological pH range. The measurement

SUBMITTER: Vologzhannikova AA 

PROVIDER: S-EPMC7825312 | biostudies-literature | 2021 Jan

REPOSITORIES: biostudies-literature