FREE-RADICAL MEDIATED INTERACTION OF ASCORBIC-ACID AND ASCORBATE/CU(II) WITH VIRAL AND PLASMID DNAS

1994-03-01
ERDEM, G
ONER, C
Önal, Ahmet Muhtar
KISAKUREK, D
OGUS, A
Previous studies indicate that ascorbic acid, when combined with copper or iron cleaves several viral DNAs. In this study, we generated the ascorbate radical anion electrochemically in a simple chemical environment without the participation of a metal ion. This solution possesses viral DNA scission activity. The absence of catalytic metal ions [Fe (III) and Cu(II)] in the incubation medium was evidenced by metal chelating agents such as desferrioxamine and EDTA. The radical quenching at high EDTA concentration was attributed to ionic strength of EDTA rather than metal chelation. The effects of antioxidants, radical scavangers, catalase, superoxide dismutase and some proteins on DNA cleavage have been tested. Cleavage may not arise directly from ascorbate free radical but the reaction of the radical form of ascorbate with oxygen may produce the actual reactive species. Aerobic oxidation of ascorbate itself strictly requires transition metal catalysts, however electrochemically produced ascorbyl radical avoided the kinetic barrier that prevented direct oxidation of ascorbic acid with oxygen and eliminated the need for the transition metal ion catalysts.
JOURNAL OF BIOSCIENCES

Suggestions

Bioproduction, structure elucidation and in vitro antiproliferative effect of eumelanin pigment from Streptomyces parvus BSB49
Bayram, Sinan; Dengiz, Çağatay; GERÇEK, Yusuf Can; ÇETİN, İdil; TOPÇUL, Mehmet Rıfkı (Springer Science and Business Media LLC, 2020-01-01)
In this study, the structure of the purified extracellular eumelanin pigment isolated from Streptomyces spp. was elucidated by detailed analysis via two different spectroscopic techniques (FT-IR and NMR). In vitro antiproliferative effects of eumelanin were evaluated on HeLa cell line. These experiments were carried out with the evaluation of the parameters including cell viability, cell index, and mitotic index. With the cell viability and cell index, IC50 concentration of eumelanin was determined as 10 μM...
In vivo examination of the effects of hydroxycinnamic acid on xenobiotic metabolizing and antioxidant enzymes
SEMİZ, ASLI; Celik-Turgut, Gurbet; KARAKURT, SERDAR; AKÇA, HAKAN; ARSLAN, ŞEVKİ; Adalı, Orhan; ŞEN, ALAATTİN (National Library of Serbia, 2017-01-01)
In the last decade, hydroxycinnamic acids (HCA) have gained increasing attention from researchers due to their antioxidant potential. The aim of this study was to examine in detail the impact of dietary HCA on particular types of P450 and also selected phase II and antioxidant enzymes in Wistar rat. HCA (10 mu M/kg/day, i.p.) was administered for ten continuous days. Examination of the activities and mRNA and protein levels revealed that CYP2B, 2C6 and 3A enzyme activities were not altered significantly, wi...
Genome-wide analysis of gene expression profiling revealed that COP9 signalosome is essential for correct expression of Fe homeostasis genes in Arabidopsis
Eroğlu, Seçkin (Springer Science and Business Media LLC, 2017-10-01)
In plant cells, either excess or insufficient iron (Fe) concentration triggers stress responses, therefore it is strictly controlled. Proteasome-mediated degradation through ubiquitination of Fe homeostasis proteins has just become the focus of research in recent years. Deactivating ubiquitin ligases, COP9 signalosome has a central importance in the translational control of various stress responses. The aim of the study was to investigate COP9 signalosome in Fe deficiency response of Strategy I plants. In s...
Gliotoxin Biosynthesis: Structure, Mechanism, and Metal Promiscuity of Carboxypeptidase GliJ
Marıon, Antoıne; Scharf, Daniel H.; Scherlach, Kirstin; Glaser, Manuel; Sievers, Holger; Schuster, Michael; Hertweck, Christian; Brakhage, Axel A.; Antes, Iris; Huber, Eva M. (American Chemical Society (ACS), 2017-07-01)
The formation of glutathione (GSH) conjugates, best known from the detoxification of xenobiotics, is a widespread strategy to incorporate sulfur into biomolecules. The biosynthesis of gliotoxin, a virulence factor of the human pathogenic fungus Aspergillus fumigatus; involves attachment of two GSH molecules and their sequential decomposition to yield two reactive thiol groups. The degradation of the GSH moieties requires the activity of the Cys-Gly carboxypeptidase GliJ, for which we describe the X-ray stru...
Kinetic analysis of aspergillus oryzae cultivations on starch
Bayındırlı, Alev; UNGAN, S (Informa UK Limited, 1991-01-01)
Cultivation of Aspergillus oryzae on starch is described as a combination of two rate processes: Starch hydrolysis and the cellular activities of the fungi including growth, enzyme production and maintenance. Kinetic models are presented to describe growth, enzyme production, starch hydrolysis and uptake of the hydrolysis products. Numerical values of the model parameters indicated that the rate controlling step of A. oryzae growth on starch was not starch hydrolysis, but the substrate uptake process. Gluco...
Citation Formats
G. ERDEM, C. ONER, A. M. Önal, D. KISAKUREK, and A. OGUS, “FREE-RADICAL MEDIATED INTERACTION OF ASCORBIC-ACID AND ASCORBATE/CU(II) WITH VIRAL AND PLASMID DNAS,” JOURNAL OF BIOSCIENCES, pp. 9–17, 1994, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/48944.