Journal Article

FZJ-2018-03777

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Interaction of Ochratoxin A and Its Thermal Degradation Product 2′R-Ochratoxin A with Human Serum Albumin

Sueck, F. ; Poór, M. ; Faisal, Z. ; Gertzen, C.FZJ* ; Cramer, B. ; Lemli, B. ; Kunsági-Máté, S. ; Gohlke, H.FZJ* ; Humpf, H.-U. (Corresponding author)

2018
MDPI Basel

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Please use a persistent id in citations: http://hdl.handle.net/2128/19190  doi:10.3390/toxins10070256

Abstract: Ochratoxin A (OTA) is a toxic secondary metabolite produced by several fungal species of the genus Penicillium and Aspergillus. 2′R-Ochratoxin A (2′R-OTA) is a thermal isomerization product of OTA formed during food processing at high temperatures. Both compounds are detectable in human blood in concentrations between 0.02 and 0.41 µg/L with 2′R-OTA being only detectable in the blood of coffee drinkers. Humans have approximately a fifty-fold higher exposure through food consumption to OTA than to 2′R-OTA. In human blood, however, the differences between the concentrations of the two compounds is, on average, only a factor of two. To understand these unexpectedly high 2′R-OTA concentrations found in human blood, the affinity of this compound to the most abundant protein in human blood the human serum albumin (HSA) was studied and compared to that of OTA, which has a well-known high binding affinity. Using fluorescence spectroscopy, equilibrium dialysis, circular dichroism (CD), high performance affinity chromatography (HPAC), and molecular modelling experiments, the affinities of OTA and 2′R-OTA to HSA were determined and compared with each other. For the affinity of HSA towards OTA, a logK of 7.0–7.6 was calculated, while for its thermally produced isomer 2′R-OTA, a lower, but still high, logK of 6.2–6.4 was determined. The data of all experiments showed consistently that OTA has a higher affinity to HSA than 2′R-OTA. Thus, differences in the affinity to HSA cannot explain the relatively high levels of 2′R-OTA found in human blood samples

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Contributing Institute(s):

1. Jülich Supercomputing Center (JSC)
2. John von Neumann - Institut für Computing (NIC)
3. Strukturbiochemie (ICS-6)

Research Program(s):

1. 511 - Computational Science and Mathematical Methods (POF3-511) (POF3-511)
2. 574 - Theory, modelling and simulation (POF3-574) (POF3-574)
3. 561 - Biological Key Regulators and Small Chemical Compounds (POF3-561) (POF3-561)
4. Forschergruppe Gohlke (hkf7_20170501) (hkf7_20170501)

Appears in the scientific report 2018

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Database coverage:
; ; ; ; BIOSIS Previews ; DOAJ Seal ; Ebsco Academic Search ; IF < 5 ; JCR ; NCBI Molecular Biology Database ; SCOPUS ; Science Citation Index Expanded ; Thomson Reuters Master Journal List ; Web of Science Core Collection

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