title: A circular dichroism study of mitochondrial transhydrogenase from beef heart.
abstract: This paper describes a circular dichroism (CD) spectroscopy study of purified proton-pumping nicotinamide nucleotide transhydrogenase from beef heart. The CD spectrum obtained was used to estimate the content of secondary structures of the purified enzyme and suggests the presence of 40-45% alpha-helical structure and long, possibly membrane-spanning alpha-helices. The spectrum was essentially unaffected by the absence or presence of transhydrogenase substrates, suggesting that the catalytic and proton-translocating activities of the enzyme occur without major rearrangements at the level of secondary structures.
authors.affiliation: Department of Biochemistry and Biotechnology, Royal Institute of Technology, Stockholm, Sweden.
authors.forename: B
authors.initials: B
authors.lastname: Persson
authors.forename: J
authors.initials: J
authors.lastname: Rydström
authors.forename: M
authors.initials: M
authors.lastname: Kubista
mesh_terms: D000818:Animals; D002417:Cattle; D002942:Circular Dichroism; D008929:Mitochondria, Heart / Q000201:enzymology*; D009243:NAD / Q000378:metabolism; D009249:NADP / Q000378:metabolism; D009250:NADP Transhydrogenases / Q000378:metabolism*; D013056:Spectrophotometry, Ultraviolet; D013379:Substrate Specificity
chemical_list: D009243:NAD; D009249:NADP; D009250:NADP Transhydrogenases