Confirmation of the Disulfide Connectivity and Strategies for Chemical Synthesis of the Four-Disulfide-Bond-Stabilized Aspergillus giganteus Antifungal Protein, AFP.
J Nat Prod
; 86(4): 782-790, 2023 04 28.
Article
in En
| MEDLINE
| ID: mdl-36847642
ABSTRACT
Emerging fungal infections require new, more efficient antifungal agents and therapies. AFP, a protein from Aspergillus giganteus with four disulfide bonds, is a promising candidate because it selectively inhibits the growth of filamentous fungi. In this work, the reduced form of AFP was prepared using native chemical ligation. The native protein was synthesized via oxidative folding with uniform protection for cysteine thiols. AFP's biological activity depends heavily on the pattern of natural disulfide bonds. Enzymatic digestion and MS analysis provide proof for interlocking disulfide topology (abcdabcd) that was previously assumed. With this knowledge, a semi-orthogonal thiol protection method was designed. By following this strategy, out of a possible 105, only 6 disulfide isomers formed and 1 of them proved to be identical with the native protein. This approach allows the synthesis of analogs for examining structure-activity relationships and, thus, preparing AFP variants with higher antifungal activity.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Fungal Proteins
/
Antifungal Agents
Language:
En
Journal:
J Nat Prod
Year:
2023
Document type:
Article
Affiliation country:
Hungary