title: Highly UV-absorbing complex in selenomethionine-substituted alcohol dehydrogenase from Sulfolobus solfataricus.
abstract: The aim of this work was to explain the previously discovered effect of significant decrease in intrinsic fluorescence intensity of SsADH caused by replacement of S atoms of methionine residues to Se (Giordano, A.; Raia, C. A. J. Fluorescence 2003, 13, 17-24) on the basis of the analysis of its 3D structure. It was found that all selenium atoms are located far from both Trp95 and Trp117 and could not cause their fluorescence quenching. At the same time, it was determined that substitution of S by Se causes enhanced protein absorption in the UV-region. This effect was explained by the formation of Se complex with some groups of protein. It was revealed that this complex does not participate in fluorescence and does not transfer excitation energy to tryptophan or tyrosine residues.
authors.affiliation: Institute of Protein Biochemistry, C. N. R., Via G. Marconi 10, I-80125 Naples, Italy.
authors.forename: Antonietta
authors.initials: A
authors.lastname: Giordano
authors.forename: Consiglia
authors.initials: C
authors.lastname: Russo
authors.forename: Carlo A
authors.initials: CA
authors.lastname: Raia
authors.forename: Irina M
authors.initials: IM
authors.lastname: Kuznetsova
authors.forename: Olga V
authors.initials: OV
authors.lastname: Stepanenko
authors.forename: Kostantin K
authors.initials: KK
authors.lastname: Turoverov
mesh_terms: D000042:Absorption; D000426:Alcohol Dehydrogenase / Q000737:chemistry*; D005453:Fluorescence; D008715:Methionine / Q000737:chemistry*; D008958:Models, Molecular; D012643:Selenium / Q000737:chemistry; D012645:Selenomethionine / Q000737:chemistry*; D048229:Sulfolobus solfataricus / Q000737:chemistry*; D014364:Tryptophan / Q000737:chemistry
chemical_list: D014364:Tryptophan; D012645:Selenomethionine; D008715:Methionine; D000426:Alcohol Dehydrogenase; D012643:Selenium