Proton transfer is one of the most important elementary processes in biology. Green fluorescent protein (GFP) serves as an important model system to elucidate the mechanistic details of this reaction, because in GFP proton transfer can be induced by light absorption. Illumination initiates proton transfer through a ‘proton-wire’, formed by the chromophore (the proton donor), water molecule W22, Ser205 and Glu222 (the acceptor), on a picosecond time scale. To obtain a more refined view of this process, we have used a combined approach of time resolved mid-infrared spectroscopy and visible pump–dump–probe spectroscopy to resolve with atomic resolution how and how fast protons move through this wire. Our results indicate that absorption of light by GFP induces in 3 ps (10 ps in D2O) a shift of the equilibrium positions of all protons in the H-bonded network, leading to a partial protonation of Glu222 and to a so-called low barrier hydrogen bond (LBHB) for the chromophore's proton, giving rise to dual emission at 475 and 508 nm. This state is followed by a repositioning of the protons on the wire in 10 ps (80 ps in D2O), ultimately forming the fully deprotonated chromophore and protonated Glu222.

Proton transfer events in GFP / Mariangela Di Donato; Luuk J.G.W. van Wilderen; Ivo H.M. van Stokkum; Thomas Cohen Stuart; John T.M. Kennis; Klaas J. Hellingwerf; Rienk van Grondelle; Marie Louise Groot. - In: PHYSICAL CHEMISTRY CHEMICAL PHYSICS. - ISSN 1463-9084. - STAMPA. - 13:(2011), pp. 16295-16305. [10.1039/C1CP20387H]

Proton transfer events in GFP

DI DONATO, MARIANGELA;
2011

Abstract

Proton transfer is one of the most important elementary processes in biology. Green fluorescent protein (GFP) serves as an important model system to elucidate the mechanistic details of this reaction, because in GFP proton transfer can be induced by light absorption. Illumination initiates proton transfer through a ‘proton-wire’, formed by the chromophore (the proton donor), water molecule W22, Ser205 and Glu222 (the acceptor), on a picosecond time scale. To obtain a more refined view of this process, we have used a combined approach of time resolved mid-infrared spectroscopy and visible pump–dump–probe spectroscopy to resolve with atomic resolution how and how fast protons move through this wire. Our results indicate that absorption of light by GFP induces in 3 ps (10 ps in D2O) a shift of the equilibrium positions of all protons in the H-bonded network, leading to a partial protonation of Glu222 and to a so-called low barrier hydrogen bond (LBHB) for the chromophore's proton, giving rise to dual emission at 475 and 508 nm. This state is followed by a repositioning of the protons on the wire in 10 ps (80 ps in D2O), ultimately forming the fully deprotonated chromophore and protonated Glu222.
2011
13
16295
16305
Mariangela Di Donato; Luuk J.G.W. van Wilderen; Ivo H.M. van Stokkum; Thomas Cohen Stuart; John T.M. Kennis; Klaas J. Hellingwerf; Rienk van Grondelle; Marie Louise Groot
File in questo prodotto:
File Dimensione Formato  
c1cp20387h.pdf

Accesso chiuso

Descrizione: articolo principale
Tipologia: Pdf editoriale (Version of record)
Licenza: Tutti i diritti riservati
Dimensione 2.68 MB
Formato Adobe PDF
2.68 MB Adobe PDF   Richiedi una copia

I documenti in FLORE sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificatore per citare o creare un link a questa risorsa: https://hdl.handle.net/2158/957755
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 40
  • ???jsp.display-item.citation.isi??? 39
social impact