UV-CD12: synchrotron radiation circular dichroism beamline at ANKA

Synchrotron radiation circular dichroism (SRCD) is a rapidly growing technique for structure analysis of proteins and other chiral biomaterials. UV-CD12 is a high-flux SRCD beamline installed at the ANKA synchrotron, to which it had been transferred after the closure of the SRS Daresbury. The beamline covers an extended vacuum-UV to near-UV spectral range and has been open for users since October 2011. The current end-station allows for temperature-controlled steady-state SRCD spectroscopy, including routine automated thermal scans of microlitre volumes of water-soluble proteins down to 170 nm. It offers an excellent signal-to-noise ratio over the whole accessible spectral range. The technique of oriented circular dichroism (OCD) was recently implemented for determining the membrane alignment of α-helical peptides and proteins in macroscopically oriented lipid bilayers as mimics of cellular membranes. It offers improved spectral quality <200 nm compared with an OCD setup adapted to a bench-top instrument, and accelerated data collection by a factor of ∼3. In addition, it permits investigations of low hydrated protein films down to 130 nm using a rotatable sample cell that avoids linear dichroism artifacts.

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Synchrotron Radiation Circular Dichroism (SRCD) Spectroscopy Investigations of the Structure and Orientation of Membrane Proteins in Oriented Lipid Bilayers

Biophysical Journal ◽

10.1016/j.bpj.2015.11.1064 ◽

2016 ◽

Vol 110 (3) ◽

pp. 191a

Author(s):

Luke S. Evans ◽

Rohanah Hussain ◽

Giuliano Siligardi ◽

Philip T.F. Williamson

Keyword(s):

Circular Dichroism ◽

Synchrotron Radiation ◽

Membrane Proteins ◽

Lipid Bilayers ◽

Circular Dichroïsm

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Oriented Synchrotron Radiation Circular Dichroism and Linear Dichroism Spectroscopy of Peptides in Model Membranes

Biophysical Journal ◽

10.1016/j.bpj.2008.12.3813 ◽

2009 ◽

Vol 96 (3) ◽

pp. 337a ◽

Cited By ~ 1

Author(s):

Barbara Perrone ◽

Andrew J. Miles ◽

Burkhard Bechinger ◽

Soren Vronning Hoffman ◽

B.A. Wallace

Keyword(s):

Circular Dichroism ◽

Synchrotron Radiation ◽

Linear Dichroism ◽

Model Membranes ◽

Circular Dichroïsm

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Spectroscopy of model-membrane liposome-protein systems: complementarity of linear dichroism, circular dichroism, fluorescence and SERS

Emerging Topics in Life Sciences ◽

10.1042/etls20200354 ◽

2021 ◽

Author(s):

Anastasiia Tukova ◽

Alison Rodger

Keyword(s):

Circular Dichroism ◽

Lipid Bilayers ◽

Resonance Energy ◽

Lipid Vesicles ◽

Linear Dichroism ◽

Surface Enhanced Raman Spectroscopy ◽

Cellular Systems ◽

Spectroscopic Techniques ◽

Wide Range ◽

Circular Dichroïsm

A range of membrane models have been developed to study components of cellular systems. Lipid vesicles or liposomes are one such artificial membrane model which mimics many properties of the biological system: they are lipid bilayers composed of one or more lipids to which other molecules can associate. Liposomes are thus ideal to study the roles of cellular lipids and their interactions with other membrane components to understand a wide range of cellular processes including membrane disruption, membrane transport and catalytic activity. Although liposomes are much simpler than cellular membranes, they are still challenging to study and a variety of complementary techniques are needed. In this review article, we consider several currently used analytical methods for spectroscopic measurements of unilamellar liposomes and their interaction with proteins and peptides. Among the variety of spectroscopic techniques seeing increasing application, we have chosen to discuss: fluorescence based techniques such as FRET (fluorescence resonance energy transfer) and FRAP (fluorescence recovery after photobleaching), that are used to identify localisation and dynamics of molecules in the membrane; circular dichroism (CD) and linear dichroism (LD) for conformational and orientation changes of proteins on membrane binding; and SERS (Surface Enhanced Raman Spectroscopy) as a rapidly developing ultrasensitive technique for site-selective molecular characterisation. The review contains brief theoretical basics of the listed techniques and recent examples of their successful applications for membrane studies.

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Investigation by Synchrotron Radiation Circular Dichroism of the Secondary Structure Evolution of Pepsin under Oxidative Environment

Foods ◽

10.3390/foods10050998 ◽

2021 ◽

Vol 10 (5) ◽

pp. 998

Author(s):

Laetitia Théron ◽

Aline Bonifacie ◽

Jérémy Delabre ◽

Thierry Sayd ◽

Laurent Aubry ◽

...

Keyword(s):

Circular Dichroism ◽

Synchrotron Radiation ◽

Secondary Structure ◽

Proteolytic Activity ◽

Digestive Enzyme ◽

Structure Evolution ◽

Food Protein ◽

Maldi Tof ◽

Kinetics Of ◽

Circular Dichroïsm

Food processing affects the structure and chemical state of proteins. In particular, protein oxidation occurs and may impair protein properties. These chemical reactions initiated during processing can develop during digestion. Indeed, the physicochemical conditions of the stomach (oxygen pressure, low pH) favor oxidation. In that respect, digestive proteases may be affected as well. Yet, very little is known about the link between endogenous oxidation of digestive enzymes, their potential denaturation, and, therefore, food protein digestibility. Thus, the objective of this study is to understand how oxidative chemical processes will impact the pepsin secondary structure and its hydrolytic activity. The folding and unfolding kinetics of pepsin under oxidative conditions was determined using Synchrotron Radiation Circular Dichroism. SRCD gave us the possibility to monitor the rapid kinetics of protein folding and unfolding in real-time, giving highly resolved spectral data. The proteolytic activity of control and oxidized pepsin was investigated by MALDI-TOF mass spectrometry on a meat protein model, the creatine kinase. MALDI-TOF MS allowed a rapid evaluation of the proteolytic activity through peptide fingerprint. This study opens up new perspectives by shifting the digestion paradigm taking into account the gastric digestive enzyme and its substrate.

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