American Journal of Bioscience and Bioengineering 2016; 4(3): 34-40 http://www.sciencepublishinggroup.com/j/bio doi: 10.11648/j.bio.20160403.11 ISSN: 2328-5885 (Print); ISSN: 2328-5893 (Online) Molecular Modeling and Docking of Ribitol Dehydrogenase Exploring Enzyme NAD + and D-psicose Interaction Hinawi A. M. Hassanin, Wanmeng Mu, Marwa Y. F. Koko, Tao Zhang, Ammar Alfarga, Mandour H. Abdelhai, Bo Jiang * State Key Laboratory of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, Wuxi, China Email address: bjiang@jiangnan.edu.cn (Bo Jiang) * Corresponding author To cite this article: Hinawi A. M. Hassanin, Wanmeng Mu, Marwa Y. F. Koko, Tao Zhang, Ammar Alfarga, Mandour H. Abdelhai, Bo Jiang. Molecular Modeling and Docking of Ribitol Dehydrogenase Exploring Enzyme NAD + and D-psicose Interaction. American Journal of Bioscience and Bioengineering. Vol. 4, No. 3, 2016, pp. 34-40. doi: 10.11648/j.bio.20160403.11 Received: April 14, 2016; Accepted: April 25, 2016; Published: May 10, 2016 Abstract: Allitol is an alcohol monosaccharide, is a reduction of D-psicose. It is functions as a cross linking of D- and L- hexoses. It existed in too small quantities in commercial sugars and is difficult to synthesize by using chemical methods. It has a hypoglycemic function, and can use as Laxative in treating of constipation, which can exploit in production of diabetes drugs. The present report investigates about the production of allitol by ribitol dehydrogenase (RDH), its action of the enzyme through homology and molecular docking studies. We have investigated ribitol dehydrogenase (RDH) from providencia alcalifaciens RIMD 1656011. The protein sequence of RDH was conducted for homology modeling through Swiss model. 3D structure revealed was docked with NAD + and D-psicose using AutoDock Vina software version 5.6. The results of homology modeling and docking studies revealed that the conserved residues of RDH were Tyr 153, Tyr 92, Ser 17 and Lys157 with NAD + , while conserved residues with D-psicose were GLN67 and ASP61. NAD + has good interaction with RDH showing grid score of -49.84, which is a good score for binding. Keywords: Homology Modeling, Docking, AutoDock Vina, Ribitol Dehydrogenase 1. Introduction Allitol is rare sugar alcohol naturally exist in Itea virginica plant and Fungus Tylopilus plumbeoviolaceus [1, 2]. Rare polyols are useful as low caloric sweetener, raw material for production of chemical compounds and research reagents [3]. Azasugars display potential medicines against diabetes, cancer and viral infections, which allitol may be use as intermediate for preparation of azasugars [4]. In addition, allitol has activity in increasing the water content of small intestine and speed up the small intestine transit and may lead to use in treating of constipation [5]. Moreover, allitol can use as an anti-crystallization agent similar as the known agents used and as effective saturation enhancer for vacuum lyophilization (freeze-drying) [6]. In Izumori strategy (Izumoring) for bio-production of hexoses, allitol located at the center of the strategy and its function as linking between D- and L-hexoses [7]. It is difficult to produce by chemical method [8]. According to Izumoring strategy, allitol can prepare by reduction of D-psicose, which ribitol dehydrogenase (RDH, EC1.1.1.56) is the enzyme responsible for reduction of D-psicose to allitol as shown in scheme 1(A) [3]. Moreover, RDH plays an important role in the production of D-ribulose from ribitol (scheme 1(B)) [9]. This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-OH group of donor with NAD + or NADP + as acceptor. RDH was characterized from various microorganisms, such as RDH from Aerobacter aerogenes, Enterobacter agglomerans, Gluconobacter oxydans, Klebsiella aerogenes, Rhodobacter sphaeroides, Klebsiella oxytoca and Zymomonas mobilis [9-15]. In a recent report, a new RDH from Providencia alcalifaciens RIMD 1656011 was cloned and characterized by our group and it exploit in production of allitol from D-psicose [16].