title: ATP changes the fluorescence lifetime of cyan fluorescent protein via an interaction with His148.
abstract: Recently, we described that ATP induces changes in YFP/CFP fluorescence intensities of Fluorescence Resonance Energy Transfer (FRET) sensors based on CFP-YFP. To get insight into this phenomenon, we employed fluorescence lifetime spectroscopy to analyze the influence of ATP on these fluorescent proteins in more detail. Using different donor and acceptor pairs we found that ATP only affected the CFP-YFP based versions. Subsequent analysis of purified monomers of the used proteins showed that ATP has a direct effect on the fluorescence lifetime properties of CFP. Since the fluorescence lifetime analysis of CFP is rather complicated by the existence of different lifetimes, we tested a variant of CFP, i.e. Cerulean, as a monomer and in our FRET constructs. Surprisingly, this CFP variant shows no ATP concentration dependent changes in the fluorescence lifetime. The most important difference between CFP and Cerulean is a histidine residue at position 148. Indeed, changing this histidine in CFP into an aspartic acid results in identical fluorescence properties as observed for the Cerulean fluorescent based FRET sensor. We therefore conclude that the changes in fluorescence lifetime of CFP are affected specifically by possible electrostatic interactions of the negative charge of ATP with the positively charged histidine at position 148. Clearly, further physicochemical characterization is needed to explain the sensitivity of CFP fluorescence properties to changes in environmental (i.e. ATP concentrations) conditions.
authors.affiliation: Laboratory of Biochemistry, Microspectroscopy Centre, Wageningen University, Wageningen, The Netherlands.
authors.forename: Jan Willem
authors.initials: JW
authors.lastname: Borst
authors.forename: Marieke
authors.initials: M
authors.lastname: Willemse
authors.forename: Rik
authors.initials: R
authors.lastname: Slijkhuis
authors.forename: Gerard
authors.initials: G
authors.lastname: van der Krogt
authors.forename: Sergey P
authors.initials: SP
authors.lastname: Laptenok
authors.forename: Kees
authors.initials: K
authors.lastname: Jalink
authors.forename: Be
authors.initials: B
authors.lastname: Wieringa
authors.forename: Jack A M
authors.initials: JA
authors.lastname: Fransen
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism* / Q000494:pharmacology; D000818:Animals; D019556:COS Cells; D055598:Chemical Phenomena / Q000187:drug effects; D002522:Chlorocebus aethiops; D005453:Fluorescence; D005454:Fluorescence Polarization; D031541:Fluorescence Resonance Energy Transfer / Q000379:methods*; D049452:Green Fluorescent Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006639:Histidine / Q000235:genetics / Q000378:metabolism*; D008164:Luminescent Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D013997:Time Factors
chemical_list: C485182:Cyan Fluorescent Protein; D008164:Luminescent Proteins; D049452:Green Fluorescent Proteins; D006639:Histidine; D000255:Adenosine Triphosphate