6533b833fe1ef96bd129c155

RESEARCH PRODUCT

Mapping protein matrix cavities in human cytoglobin through Xe atom binding

Luc MoensPaolo AscenziSylvia DewildeMartino BolognesiAlessandra PesceThorsten BurmesterThomas HankelnDaniele De Sanctis

subject

Models MolecularXenonMacromolecular SubstancesProtein ConformationBiophysicsHemeCrystallography X-RayBiochemistrychemistry.chemical_compoundHumansComputer SimulationGlobinMolecular BiologyHemeBinding SitesCytoglobinCytoglobinOxygen transportCell BiologyGlobinsGlobin foldCrystallographyPeroxidasesMyoglobinchemistryNeuroglobinBiophysicsHemoglobinPorosityProtein Binding

description

Abstract Cytoglobin is the fourth recognized globin type, almost ubiquitously distributed in human tissues; its function is still poorly understood. Cytoglobin displays a core region of about 150 residues, structurally related to hemoglobin and myoglobin, and two extra segments, about 20 residues each, at the N- and C-termini. The core region hosts a large apolar cavity, held to provide a ligand diffusion pathway to/from the heme, and/or ligand temporary docking sites. Here we report the crystal structure (2.4 A resolution, R -factor 19.1%) of a human cytoglobin mutant bearing the CysB2(38) → Ser and CysE9(83) → Ser substitutions (CYGB*), treated under pressurized xenon. Three Xe atoms bind to the heme distal site region of CYGB* mapping the protein matrix apolar cavity. Despite the conserved globin fold, the cavity found in CYGB* is structured differently from those recognized to play a functional role in myoglobin, neuroglobin, truncated hemoglobins, and Cerebratulus lacteus mini-hemoglobin.

yearjournalcountryeditionlanguage
2004-01-01Biochemical and Biophysical Research Communications
https://doi.org/10.1016/j.bbrc.2004.03.007