Differences in functional cross-talk between loops C and D in two mitochondrial cytochromes.

ABSTRACT: The heme in the protein cytochrome (cyt) c is surrounded by loops C and D that differ in their sequences across species. Mutations G41S and Y48H in human (hu) cyt c are associated with thrombocytopenia and have been extensively studied. Herein, we describe effects of the same mutations in horse heart (hh) cyt c and make comparisons to those in the hu protein. While wild-type (WT) hu and hh cyt c proteins have similar global stabilities, unfolding of the hh protein is less cooperative. The differences are further amplified in the mutants. Loop dynamics were probed computationally through MD simulations and experimentally by characterizing the alkaline transition. With G41S and Y48H mutations in hh cyt c, loop C made fewer contacts with loop D and the dynamics of loop D were enhanced. Only t

SUBMITTER: Shin DW 

PROVIDER: S-EPMC12768443 | biostudies-literature | 2026 Mar

REPOSITORIES: biostudies-literature