Aspergillus nidulans thermostable Arginine deiminase-Dextran conjugates with enhanced molecular stability, proteolytic resistance, pharmacokinetic properties and anticancer activity

Publication date: Available online 21 September 2019Source: Enzyme and Microbial TechnologyAuthor(s): Ashraf S.A. El-Sayed, Ahmed A. Shindia, Azza A. Abou Zeid, Amany M. Yassin, Mahmoud Z. Sitohy, Basel SitohyAbstractThe potential anticancer activity of arginine deiminase (ADI) via deimination of L-arginine into citrulline has been extensively verified against various arginine-auxotrophic tumors, however, the higher antigenicity, structural instability and in vivo proteolysis are the major challenges that limit this enzyme from further clinical implementation. Since, this clinically applied enzyme was derived from Mycobacterium spp, thus, searching for ADI from eukaryotic microbes “especially thermophilic fungi” could have a novel biochemical, conformational and catalytic properties. Aspergillus nidulans ADI was purified with 5.3 folds, with molecular subunit structure 48 kDa and entire molecular mass 120 kDa, ensuring its homotrimeric identity. The peptide fingerprinting analysis revealing the domain Glu95-Gly96-Gly97 as the conserved active site of A. nidulans ADI, with higher proximity to Mycobacterium ADI clade IV. In an endeavor to fortify the structural stability and anticancer activity of A. nidulans ADI, the enzyme was chemically modified with dextran. The optimal activity of Dextran-ADI conjugates was determined at 0.08:20 molar ratio of ADI: Dextran, with an overall increase to ADI molecular subunit mass to ∼100 kDa. ADI was conjugated with dextran via t...
Source: Enzyme and Microbial Technology - Category: Biotechnology Source Type: research