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Glycosyltransferases are ubiquitous enzymes play vital role in numerous aspects of living organisms and are involved in secondary metabolism. Also known as uridine diphosphate (UDP) glycosyltransferases (UGTs) are engaged in detoxification in living organisms. UGT76E1 is a member of 76E family of UGT comprising of 453 amino acids. The gene for glycosyltransferase, UGT76E1 from Arabidopsis thaliana was expressed and purified through affinity chromatography.Site directed mutagenesis was performed to change hydrophilic threonine (T) into hydrophobic alanine (A) at 134 position. Afterwards the activity of mutant enzyme was analyzed through mass spectrometry. Novobiocin and kaempherol were used as acceptor moleculesfor activity tests. After mutagenesis the mutant UGT76E1T134A lost its activity with its donor sugar UDP glucose, as no peak was observed for the required products glc-novobiocin and glc-kaempherol at 773 and 447 in mass spectrum respectively. The mutant did not attainany new activity with UDP rhamnose also. Complete loss of activity of UGT76E1T134A with UDP glucose as donor sugar suggested for the presence of significant peptides at the site of mutation.The current results showed that glycosyltransferases can be modified to use different substrates by site directed mutagenesis. This UGT enzyme modification could open new horizon in the development of new drugs for cancer treatment. © 2015 Friends Science Publishers [ABSTRACT FROM AUTHOR]

Glucose oxidase (ß-D glucose: oxygen-oxidoreductase, GOD) is of prime importance in food and health industries for the production of gluconic acid, maintaining flavor and color stability and quantification of glucose in blood and urine etc. Aspergillus niger is one of the key producers of GOD. We report the genetic diversity assessment of A. niger University of Agriculture Faisalabad (UAF) wild type strain and its seventeen mutants. The mutants developed via four mutagens viz., UV rays, gamma rays, ethidium bromide and MNNG for the hyper production of Glucose Oxidase. Molecular typing methods have been used for the detection of polymorphism within the members of any fungal genera as well as species. However, this is the pioneering attempt which focuses on detection of polymorphism in A. niger UAF parent strain and its mutants using RAPD and SSRs. Out of 26 RAPD primers used in the study, 12 produced polymorphic banding pattern amplifying 125 bands with an average of 10.41 fragments per primer. The most diverse mutants were UV-180-A and UV-180-B. All the mutants and a wild type strain were divided into six different groups except the mutant EMS-F which appeared unclustered. For SSR analysis, six different microsatellites were applied (AN01-06), which amplified 2-3 alleles in the mutants ranging from 100-450 bp size. The results revealed the existence of high genetic variability among the mutant strains and a wild type strain. [ABSTRACT FROM AUTHOR]