Charge-Disproportionation Symmetry Breaking Creates a Heterodimeric Myoglobin Complex with Enhanced Affinity and Rapid Intracomplex Electron Transfer.

ABSTRACT: We report rapid photoinitiated intracomplex electron transfer (ET) within a "charge-disproportionated" myoglobin (Mb) dimer with greatly enhanced affinity. Two mutually supportive Brownian Dynamics (BD) interface redesign strategies, one a new "heme-filtering" approach, were employed to "break the symmetry" of a Mb homodimer by pairing Mb constructs with complementary highly positive and highly negative net surface charges, introduced through D/E → K and K → E mutations, respectively. BD simulations using a previously developed positive mutant, Mb(+6) = Mb(D44K/D60K/E85K), led to construction of the complementary negative mutant Mb(-6) = Mb(K45E, K63E, K95E). Simulations predict the pair will form a well-defined complex comprising a tight ensemble of conformations with nearly parallel heme

SUBMITTER: Trana EN 

PROVIDER: S-EPMC5068489 | biostudies-literature | 2016 Sep

REPOSITORIES: biostudies-literature