Screening Microbes Isolated From Melalap, Crocker Range For Inhibitors Against Both Prokaryotic and Eukaryotic Signal Transduction and Isocitrate Lyase In Mycobacterium

Abstract

In this study, 65 soil samples from underneath identified plants were collected upsfeam along the Melalap river. One hundred and thirty-six actinomycetes and ten microflrngi were isolated using selective isolation methods. These pure isolates were cultured aerobically for secondary metabolite production. They were screened for inhibitors against three yeast-based molecular targeted screenings: protein phosphatase 1 (PPl), glycogen syrthase kinas€ 3p (GSK-39), Ras/ Raf-l protein-protein interaction, aad two Mycob acterium-based screening systems: isocitrate lyase (ICL) of the glyoxylate pathway and PhoP-PhoR two component signal transduction system. Three extracts (H11329, Hi i337 andHl1402) were toxic to yeast in Ras/Raf-l screening, nine extracts were toxic to yeast in PPl screening (Hl1293, H11298, Hl1300, H11301, Ht 1302, H11304, Hll3l7, H11339 and H11402). One actinomycete strain Hl1299 showed weak inlfbition to PP I . Two extacts (H 1 1 329 and II1 13 64) showed weak inhibitory activify and tlree extracts (Hl1339, H11337, Hll402) showed toxicity in the GSK-39 yeast screening. Five extracts (H11310, H11317, H11337, H11346 and H11383) showed toxic effect in the ICL screening system, and one extract (Hl1392) possibly showed weak inhibition to the PhoP-PhoR two component system. It is interesting that Hl 1383 has th€ same inhibition characteristic as H7763, a presumptive ICL inhibitor with a wide partial inhibition zone on acetate plate (Dain, 2003).