Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Citation - WoS: 7Citation - Scopus: 6Water-Soluble Antioxidant Potential of Melon Lines Grown in Turkey(Taylor and Francis Ltd., 2012) Şelale, Hatice; Şığva, Hasan Özgür; Çelik, İbrahim; Doğanlar, Sami; Frary, AnneThe antioxidant potential of 42 melon (Cucumis melo) lines including six cultivars grown in Turkey was assessed by measuring total water-soluble antioxidant capacity, phenolic and vitamin C contents. The lines showed significant variability for all three antioxidant parameters with breeding lines having higher antioxidant capacity and phenolic content than some popular cultivars. Different types of melons also showed significantly different antioxidant potentials. Thus, galia and ananas types showed a higher mean antioxidant capacity and phenolic content than the other tested types (yuva, kislik, canary, and charentais). Correlation analysis between antioxidant parameters showed a significant correlation between water-soluble antioxidant capacity and phenolic content. © 2012 Copyright Taylor and Francis Group, LLC.Article Citation - WoS: 25Citation - Scopus: 23Structural Alteration of Cofactor Specificity in Corynebacterium 2,5-Diketo Acid Reductase(John Wiley and Sons Inc., 2004) Şanlı Mohamed, Gülşah; Banta, Scott; Anderson, Stephen; Blaber, MichaelCarynebacterium 2,5-Diketo-D-gluconic acid reductase (2,5-DKGR) catalyzes the reduction of 2,5-diketo-D-gluconic acid (2,5-DKG) to 2-Keto-L-gulonic acid (2-KLG). 2-KLG is an immediate precursor to L-ascorbic acid (vitamin C), and 2,5-DKGR is, therefore, an important enzyme in a novel industrial method for the production of vitamin C. 2,5-DKGR, as with most other members of the aldo-keto reductase (AKR) superfamily, exhibits a preference for NADPH compared to NADH as a cofactor in the stereo-specific reduction of substrate. The application of 2,5-DKGR in the industrial production of vitamin C would be greatly enhanced if NADH could be efficiently utilized as a cofactor. A mutant form of 2,5-DKGR has previously been identified that exhibits two orders of magnitude higher activity with NADH in comparison to the wild-type enzyme, while retaining a high level of activity with NADPH. We report here an X-ray crystal structure of the holo form of this mutant in complex with NADH cofactor, as well as thermodynamic stability data. By comparing the results to our previously reported X-ray structure of the holo form of wild-type 2,5-DKGR in complex with NADPH, the structural basis of the differential NAD(P)H selectivity of wild-type and mutant 2,5-DKGR enzymes has been identified.