Effects of hydrogen sulfide on the heme coordination structure and catalytic activity of the globin-coupled oxygen sensor AfGcHK

Kód výsledku v IS VaVaI

RIV/00216208:11310/16:10329066 - isvavai.cz

Nalezeny alternativní kódy

RIV/61388971:_____/16:00467701

Výsledek na webu

https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=EAGpQobcZ5

DOI - Digital Object Identifier

10.1007/s10534-016-9947-z

Jazyk výsledku

angličtina

Název v původním jazyce

Effects of hydrogen sulfide on the heme coordination structure and catalytic activity of the globin-coupled oxygen sensor AfGcHK

Popis výsledku v původním jazyce

AfGcHK is a globin-coupled histidine kinase that is one component of a two-component signal transduction system. The catalytic activity of this heme-based oxygen sensor is due to its C-terminal kinase domain and is strongly stimulated by the binding of O-2 or CO to the heme Fe(II) complex in the N-terminal oxygen sensing domain. Hydrogen sulfide (H2S) is an important gaseous signaling molecule and can serve as a heme axial ligand, but its interactions with heme-based oxygen sensors have not been studied as extensively as those of O-2, CO, and NO. To address this knowledge gap, we investigated the effects of H2S binding on the heme coordination structure and catalytic activity of wild-type AfGcHK and mutants in which residues at the putative O-2-binding site (Tyr45) or the heme distal side (Leu68) were substituted. Adding Na2S to the initial OH-bound 6-coordinate Fe(III) low-spin complexes transformed them into SH-bound 6-coordinate Fe(III) low-spin complexes. The Leu68 mutants also formed a small proportion of verdoheme under these conditions. Conversely, when the heme-based oxygen sensor EcDOS was treated with Na2S, the initially formed Fe(III)-SH heme complex was quickly converted into Fe(II) and Fe(II)-O-2 complexes. Interestingly, the autophosphorylation activity of the heme Fe(III)-SH complex was not significantly different from the maximal enzyme activity of AfGcHK (containing the heme Fe(III)-OH complex), whereas in the case of EcDOS the changes in coordination caused by Na2S treatment led to remarkable increases in catalytic activity.

Název v anglickém jazyce

Effects of hydrogen sulfide on the heme coordination structure and catalytic activity of the globin-coupled oxygen sensor AfGcHK

Popis výsledku anglicky

AfGcHK is a globin-coupled histidine kinase that is one component of a two-component signal transduction system. The catalytic activity of this heme-based oxygen sensor is due to its C-terminal kinase domain and is strongly stimulated by the binding of O-2 or CO to the heme Fe(II) complex in the N-terminal oxygen sensing domain. Hydrogen sulfide (H2S) is an important gaseous signaling molecule and can serve as a heme axial ligand, but its interactions with heme-based oxygen sensors have not been studied as extensively as those of O-2, CO, and NO. To address this knowledge gap, we investigated the effects of H2S binding on the heme coordination structure and catalytic activity of wild-type AfGcHK and mutants in which residues at the putative O-2-binding site (Tyr45) or the heme distal side (Leu68) were substituted. Adding Na2S to the initial OH-bound 6-coordinate Fe(III) low-spin complexes transformed them into SH-bound 6-coordinate Fe(III) low-spin complexes. The Leu68 mutants also formed a small proportion of verdoheme under these conditions. Conversely, when the heme-based oxygen sensor EcDOS was treated with Na2S, the initially formed Fe(III)-SH heme complex was quickly converted into Fe(II) and Fe(II)-O-2 complexes. Interestingly, the autophosphorylation activity of the heme Fe(III)-SH complex was not significantly different from the maximal enzyme activity of AfGcHK (containing the heme Fe(III)-OH complex), whereas in the case of EcDOS the changes in coordination caused by Na2S treatment led to remarkable increases in catalytic activity.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10608 - Biochemistry and molecular biology

Projekt

GA15-19883S: Mechanismus intraproteinového/mezidoménového přenosu signálu u modelových hemových senzorových proteinů

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2016

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Biometals

ISSN

0966-0844

e-ISSN

—

Svazek periodika

29

Číslo periodika v rámci svazku

4

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

15

Strana od-do

715-729

Kód UT WoS článku

000381144200012

EID výsledku v databázi Scopus

2-s2.0-84978139569