Unique Aggregation of Sterigmatocystin in Water Yields Strong and Specific Circular Dichroism Response Allowing Highly Sensitive and Selective Monitoring of Bio-Relevant Interactions.
Mar Drugs
; 17(11)2019 Nov 06.
Article
in En
| MEDLINE
| ID: mdl-31698712
ABSTRACT
We demonstrated the hitherto unknown property of the mycotoxin sterigmatocystin (STC) to provide homogeneous solutions in aqueous medium by forming a unique aggregate type (not formed by analogous aflatoxins), characterized by exceptionally strong circular dichroism (CD) bands in the 300-400 nm range. Results showed that these CD bands do not originate from intrinsic STC chirality but are a specific property of a peculiar aggregation process similar to psi-DNA CD response. Transmission electron microscopy (TEM) experiments revealed a fine fiber network resembling a supramolecular gel structure with helical fibers. Thermodynamic studies of aggregates by differential scanning calorimetry (DSC) revealed high reversibility of the dominant aggregation process. We demonstrated that the novel STC psi-CD band at 345 nm could be applied at biorelevant conditions (100 nanomolar concentration) and even in marine-salt content conditions for specific and quantitative monitoring of STC. Also, we showed that STC strongly non-covalently interacts with ds-DNA with likely toxic effects, thus contrary to the previous belief requiring prior enzyme epoxidation.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Sterigmatocystin
/
Water
/
Circular Dichroism
Type of study:
Diagnostic_studies
Language:
En
Journal:
Mar Drugs
Journal subject:
BIOLOGIA
/
FARMACOLOGIA
Year:
2019
Type:
Article
Affiliation country:
Croatia