Characterization of Heme Orientational Disorder in a Myoglobin Reconstituted with a Trifluoromethyl-Group-Substituted Heme Cofactor
| Autor: | Yasuhiko Yamamoto, Fumiaki Yumoto, Saburo Neya, Ryu Nishimura, Miho Watanabe, Akihiro Suzuki, Kosuke Namiki, Yuki Kanai, Tomokazu Shibata, Ayaka Harada, Shunpei Nakamura, Toshiya Senda |
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| Rok vydání: | 2017 |
| Předmět: |
Stereochemistry
Mutation Missense Heme Crystal structure Crystallography X-Ray 010402 general chemistry 01 natural sciences Biochemistry Cofactor chemistry.chemical_compound Side chain Animals Moiety Binding Sites Sperm Whale biology Myoglobin 010405 organic chemistry Chemistry 0104 chemical sciences Amino Acid Substitution biology.protein Chemical stability Salt bridge |
| Zdroj: | Biochemistry. 56:4500-4508 |
| ISSN: | 1520-4995 0006-2960 |
| DOI: | 10.1021/acs.biochem.7b00457 |
| Popis: | The orientation of a CF3-substituted heme in sperm whale myoglobin and L29F, H64L, L29F/H64Q, and H64Q variant proteins has been investigated using 19F NMR spectroscopy to elucidate structural factors responsible for the thermodynamic stability of the heme orientational disorder, i.e., the presence of two heme orientations differing by a 180° rotation about the 5–15 meso axis, with respect to the protein moiety. Crystal structure of the met-aquo form of the wild-type myoglobin reconstituted with 13,17-bis(2-carboxylatoethyl)-3,8-diethyl-2,12,18-trimethyl-7-trifluoromethylporphyrinatoiron(III), determined at resolution of 1.25 A, revealed the presence of the heme orientational disorder. Alterations of the salt bridge between the heme 13-propionate and Arg45(CD3) side chains due to the mutations resulted in equilibrium constants of the heme orientational disorder ranging between 0.42 and 1.4. Thus, the heme orientational disorder is affected by the salt bridge associated with the heme 13-propionate side cha... |
| Databáze: | OpenAIRE |
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