Exploring the Roles of Heme Type and Histidine -Tyrosine Cross -Link in Heme-Copper Oxidases Using a Myoglobin Model

Wang, Ningyan

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Description

Title

Exploring the Roles of Heme Type and Histidine -Tyrosine Cross -Link in Heme-Copper Oxidases Using a Myoglobin Model

Author(s)

Wang, Ningyan

Issue Date

2007

Doctoral Committee Chair(s)

Lu, Yi

Department of Study

Biochemistry

Discipline

Biochemistry

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

Chemistry, Biochemistry

Language

eng

Abstract

Novel oxygen reactivity is observed in our model protein (CuBMb) which reproduces the most essential components of HCO active site. In order to improve this artificial model to inhibit its side reaction with oxygen and channel it toward oxidase reactivity, more features were introduced into the CuBMb model in this study: (1) synthetic heme cofactors are used to replace the natural one of the protein, resulting in ∼20 fold inhibition of the side reaction; (2) a novel semi-synthetic system (Expressed Protein Ligation) is also established that may introduce new features such as the Tyr-His cross-linking structure in HCO to the model by direct incorporation of unnatural amino acid(s) into the protein sequence. These strategies demonstrate the power of combining the strength of biological, chemical and modern analytical techniques to create accurate biosynthesis models of protein active sites which can provide insight not easily achievable through other studies, thereby complementing the knowledge gained from both native protein and synthetic model studies.

Graduation Semester

2007

Type of Resource

text

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