Title

HNO Binding in a Heme Protein: Structures, Spectroscopic Properties, and Stabilities

Document Type

Article

Publication Date

9-1-2011

Department

Chemistry and Biochemistry

Abstract

HNO can interact with numerous heme proteins, but atomic level structures are largely unknown. In this work, various structural models for the first stable HNO heme protein complex, MbHNO (Mb, myoglobin), were examined by quantum chemical calculations. This investigation led to the discovery of two novel structural models that can excellently reproduce numerous experimental spectroscopic properties. They are also the first atomic level structures that can account for the experimentally observed high stabilities. These two models involve two distal His conformations as reported previously for MbCNR and MbNO. However, a unique dual hydrogen bonding feature of the HNO binding was not reported before in heme protein complexes with other small molecules such as CO, NO, and O-2. These results shall facilitate investigations of HNO bindings in other heme proteins.

Publication Title

Journal of the American Chemical Society

Volume

133

Issue

35

First Page

13814

Last Page

13817