TY  - JOUR
A1  - Hornemann, Andrea
A1  - Eichert, Diane Madeleine
A1  - Hoehl, Arne
A1  - Tiersch, Brigitte
A1  - Ulm, Gerhard
A1  - Ryadnov, Maxim G.
A1  - Beckhoff, Burkhard
T1  - Investigating Membrane-Mediated Antimicrobial Peptide Interactions with Synchrotron Radiation Far-Infrared Spectroscopy
JF  - ChemPhysChem : a European journal of chemical physics and physical chemistry
N2  - Synchrotron radiation-based Fourier transform infrared spectroscopy enables access to vibrational information from mid over far infrared to even terahertz domains. This information may prove critical for the elucidation of fundamental bio-molecular phenomena including folding-mediated innate host defence mechanisms. Antimicrobial peptides (AMPs) represent one of such phenomena. These are major effector molecules of the innate immune system, which favour attack on microbial membranes. AMPs recognise and bind to the membranes whereupon they assemble into pores or channels destabilising the membranes leading to cell death. However, specific molecular interactions responsible for antimicrobial activities have yet to be fully understood. Herein we probe such interactions by assessing molecular specific variations in the near-THz 400-40 cm(-1) range for defined helical AMP templates in reconstituted phospholipid membranes. In particular, we show that a temperature-dependent spectroscopic analysis, supported by 2D correlative tools, provides direct evidence for the membrane-induced and folding-mediated activity of AMPs. The far-FTIR study offers a direct and information-rich probe of membrane-related antimicrobial interactions.
KW  - antimicrobial peptides
KW  - electrostatic interactions
KW  - IR spectroscopy
KW  - phospholipid membranes
KW  - protein folding
Y1  - 2022
U6  - https://doi.org/10.1002/cphc.202100815
SN  - 1439-4235
SN  - 1439-7641
VL  - 23
IS  - 4
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Fabian, Heinz
A1  - Gast, Klaus
A1  - Laue, Michael
A1  - Jetzschmann, Katharina J.
A1  - Naumann, Dieter
A1  - Ziegler, Andreas
A1  - Uchanska-Ziegler, Barbara
T1  - IR spectroscopic analyses of amyloid fibril formation of beta(2)-microglobulin using a simplified procedure for its in vitro generation at neutral pH
JF  - Biophysical chemistry : an international journal devoted to the physical chemistry of biological phenomena
N2  - beta(2)-microglobulin (beta(2)m) is known to be the major component of fibrillar deposits in the joints of patients suffering from dialysis-related amyloidosis. We have developed a simplified procedure to convert monomeric recombinant beta(2)m into amyloid fibrils at physiological pH by a combination of stirring and heating, enabling us to follow conformational changes associated with the assembly by infrared spectroscopy and electron microscopy. Our studies reveal that fibrillogenesis begins with the formation of relatively large aggregates, with secondary structure not significantly altered by the stirring-induced association. In contrast, the conversion of the amorphous aggregates into amyloid fibrils is associated with a profound re-organization at the level of the secondary and tertiary structures, leading to non-native like parallel arrangements of the beta-strands in the fully formed amyloid structure of beta(2)m. This study highlights the power of an approach to investigate the formation of beta(2)m fibrils by a combination of biophysical techniques including IR spectroscopy.
KW  - Amyloid fibril
KW  - beta(2)-microglobulin
KW  - Amyloidogenesis
KW  - IR spectroscopy
Y1  - 2013
U6  - https://doi.org/10.1016/j.bpc.2013.05.001
SN  - 0301-4622
VL  - 179
IS  - 5
SP  - 35
EP  - 46
PB  - Elsevier
CY  - Amsterdam
ER  -