XIV
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International Conference on Molecular Spectroscopy, Białka Tatrzańska 2017
224
T2: P–9
I nteraction of HMGB1 and HMGB2 chromosomal proteins
with DNA in presence of cisplatin
Chikhirzhina Elena
1
, Veronika Travkina
1
, and Polyanichko Alexander
1,2
1
Institute of Cytology, Russian Science Academy, 4 Tikhoretsky ave., Saint-Petersburg, 194064,
Russian Federation, e-mail: travkinaveronika@gmail.com
2
Saint Petersburg State University, 7/9 Universitetskaya nab., Saint-Petersburg, 199034,
Russian Federation
Cis
-DDP (cisplatin) is a chemotherapeutic agent widely used to treat several types of human
malignancies. Biological activity of platinum coordination compounds based on the ability to
form stable adducts on DNA. A biochemical and structural analysis of cis-DDP adducts reveals
major distortions of the DNA double helix including bending and unwinding and prohibits its
proper functioning in living cell. Some nuclear proteins can recognize the distortions of DNA.
Among such proteins, the most interesting are the proteins HMGB1 and HMGB2. Non-histone
chromosomal proteins HMGB1/2 are the members of a large family of High Mobility Group
proteins and provide additional levels of structural and functional unity of chromatin. Despite
the fact that HMGB1/2 present in the cells of all investigated organisms their functions remain
unclear. Sometimes HMGB1/2 are considered as an architectural transcription factor, because
they are involved in formation of DNA–protein complexes responsible for activation of gene
transcription. The interest to these proteins is also explained by the fact that structural motifs
similar to its DNA-binding domains (known as HMGB domains) were found in many regulatory
proteins; all these motifs were shown to be active in DNA binding.
We have studied the conformational changes of DNA upon the interaction with proteins
HMGB1 and HMGB2 in presence of cis-DDP using UV Circular Dichroism (CD) and IR/UV
absorption spectroscopy. It was shown that both HMGB1/2 proteins are able to interact with cis-
DDP, forming coordination complexes involving sulfur atoms of amino acid residues in the
DNA-binding domains. However, the manner of the interaction of the proteins with cis-DDP is
different for HMGB1 and 2. We also observe two different mechanisms of the interaction of
HMGB1 and HMGB2 with DNA damaged by cisplatin. The interaction HMGB2 show higher
affinity to DNA/cisplatin adducts compared to HMGB1. We suggest that HMGB2 protein forms
supramolecular structures with DNA-modified by platinum (II). Thus, despite the similarity in
their primary structures, the mechanisms of the interactions of HMGB1 and HMGB2 with DNA
are different, that might determine the differences in their functioning in the living cell.
Keywords: circular dichroism; FTIR spectroscopy; non-histone chromosomal proteins HMGB1 and HMGB2;
DNA/proteins interactions; cisplatin
Acknowledgment
The work was supported by Russian Foundation for Basic Research (RFBR, grant 15-08-06876).
XIV
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International Conference on Molecular Spectroscopy, Białka Tatrzańska 2017
225
T2: P–10
Surface-enhanced Raman spectroscopy and principal component
analysis for the detection and identification of human fungal pathogens
Evelin Witkowska
1
, Agnieszka Kamińska
1
, Tomasz Jagielski
2
,
Aneta Kowalska
1
, and Jacek Waluk
1
1
Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw,
Poland, e-mail: ewitkowska@ichf.edu.pl,akamin@ichf.edu.pl
2
University of Warsaw, Faculty of Biology, Department of Applied Microbiology, I. Miecznikowa 1,
02-096 Warsaw, Poland
The work demonstrates that surface-enhanced Raman spectroscopy (SERS) coupled with
principal component analysis (PCA) can serve as a fast and reliable technique for detection and
identification of human fungal pathogens, such as Trychophyton rubrum (Fig. 1), Candida
krusei, Scopulariopsis brumptii, and Aspergillus flavus. Fungal infections have become one of
the leading infectious cause of morbidity and mortality among hospitalized patients and/or
immunocompromised hosts [1]. Hence, there is a strong need for the development of new
technologies allowing for fast and reliable diagnosis of fungal diseases.
Our study shows that SERS technique effectively distinguishes between selected common
fungal pathogens, thus offers taxonomic affiliation of fungi within several minutes.
Additionally, the PCA analysis allows to perform the statistical classification of fungal
pathogens studied and to identify the fungal spectrum directly from a clinical sample [2].
Fig. 1. SEM image and SERS spectrum of T. rubrum.
Keywords: fungi; mycosis; SERS, PCA
References
[1]
B. Willinger, Curr. Drug Targets 7 (2006) 513.
[2] E. Witkowska, T. Jagielski, A. Kamińska, A. Kowalska, A. Hryncewicz-Gwóźdź, J. Waluk,
Anal. Methods 8 (2016) 8427.
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