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Proton Transfer and Protein Conformation Dynamics in Photosensitive Proteins by Time-resolved Step-scan Fourier-transform Infrared Spectroscopy
Published on: June 27, 2014
Surface-mediated proton-transfer reactions in membrane-bound proteins
Pia Adelroth1, Peter Brzezinski
1Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences, Stockholm University, Svante Arrhenius väg 12, SE-106 91 Stockholm, Sweden. piaa@dbb.su.se
Biochimica Et Biophysica Acta
|April 22, 2004
Summary
Biological energy conversion relies on proton gradients across membranes, generated by protein complexes. This review explores how protein surfaces and water interfaces facilitate proton delivery to these complexes, using examples from bacterial reaction centers and cytochrome c oxidase.
Area of Science:
- Biochemistry
- Molecular Biology
- Bioenergetics
Background:
- The chemiosmotic theory posits proton electrochemical potential difference (proton gradient) as a key intermediate in biological energy conversion.
- Membrane-bound protein complexes generate and utilize proton gradients via specific proton-transfer pathways.
- Understanding proton dynamics at the protein-membrane interface is crucial for elucidating energy transduction mechanisms.
Purpose of the Study:
- To review the role of the protein-membrane surface and the surface-bulk water interface in proton delivery dynamics.
- To elucidate the mechanisms governing proton transfer to membrane-bound protein complexes.
- To highlight the importance of interfacial water in proton conduction.
Main Methods:
- Literature review focusing on experimental studies of proton transfer mechanisms.
- Analysis of data from bacterial photosynthetic reaction centers (RCs) and cytochrome c oxidase (CcO).
- Integration of concepts from biophysics and physical chemistry to explain interfacial proton dynamics.
Main Results:
- The protein-membrane surface and associated water layers significantly influence proton delivery efficiency.
- Interfacial water plays a critical role in mediating proton transfer to the active sites of proton-transferring proteins.
- Specific examples from RCs and CcO illustrate how protein structure dictates proton conduction pathways.
Conclusions:
- The protein-membrane interface is a critical functional site for efficient proton delivery in biological energy conversion.
- Interfacial water dynamics are integral to the mechanism of proton translocation across membranes.
- Further research into these interfacial phenomena will advance our understanding of bioenergetics and related diseases.
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