Screening and purification for inhibitors of GSK3 and RAS/RAF from actinomycetes and myrmecodia tuberosa

Mak, Ken Hing (2005) Screening and purification for inhibitors of GSK3 and RAS/RAF from actinomycetes and myrmecodia tuberosa. Universiti Malaysia Sabah. (Unpublished)


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Soil microbes especially actinomycetes are a main source of the production of bioactive metabolites through its secondary metabolisms. Therefore, soils are collected at the rain forest of Danum valley during the field trip to Danum Valley. The collected soil samples are used for the isolation and purification of actinomycetes using humic acid vitamin agar and oatmeal agar. Purified actinomycetes are fermented by using mannitolpeptone medium for the production of secondary metabolites. Besides that, one assign strain of actinomycetes, H7372, which is isolated by Cheah, is fermented using the KF-7L fermentor. Fermentation of the actinomycetes are ended after 120 hours and harvested by adding acetone at the proportion of 1:1 (v/v). Acetone extract obtained from the fermentation is used for the screening for bioactive metabolites against mammalian GSK- 3β and Ras/Raf-1 protein interaction. Besides that, Myrmecodia tuberosa, which is a medicinal plant that found in the forest of Sabah is also tested. This medicinal plant is extracted using two different extraction methods, which are solid-liquid extraction system and liquid-liquid extraction system. From the liquid-liquid extraction, two different layers, which are the methanol aqueous and chloroform layer are used in the screening against mammalian GSK -3β and also Ras/Raf-1 protein interaction. In the screening of bioactive metabolites against mammalian GSK-3β, H10075 and H10079, which is the gsk-3 null mutant transform with pKT10-GSK3β and Yep24-MCK1 respectively. Yeast two-hybrid screening system is used in the screening for inhibitors against Ras/Raf-1 protein interaction. Total of 7 of 94 new isolates of Danum Valley, which are H11695, H11722, Hl1821, H11853, Hl1855, H11856 and H11857, showing inhibition in the screening against GSK-3β While, 9 of 94 isolates, which are H11822, H11855, H11856, H118S7, H11858, H11861, H11867, H11878 and H11879 showing inhibition against Ras/Raf-1. The medicinal plants extract did not show inhibition effects against both of screening system. The inhibitor can be distinguished into two types that are potential and toxic inhibitor. Potential inhibitors are the inhibitor that will inhibit the abnormal cells while permitting the growth of normal cells; meanwhile toxic inhibitors are inhibitor that will inhibit both of the normal and abnormal cell growth in the RaslRaf-1 and GSK-3 pathway.

Item Type: Academic Exercise
Uncontrolled Keywords: soil microbes, actinomycetes, bioactive metabolite, Danum valley, Myrmecodia tuberosa, inhibitor
Subjects: Q Science > QR Microbiology
Divisions: SCHOOL > School of Science and Technology
Date Deposited: 16 Dec 2013 05:00
Last Modified: 11 Oct 2017 07:17

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