| Broad Institute MLPCN Streptokinase Expression Inhibition Project - BioAssay Summary The goal of the project is to identify and develop novel antibiotic small molecules through inhibiting streptokinase (SK) expression in group A streptococcus (GAS). Based on the critical role of SK in GAS pathogenicity, we are attempting to identify chemical compounds that specifically reduce the expression of bacterial SK, without interfering with bacterial viability. Specifically, a probe is a more .. |
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Description: Broad Institute of MIT and Harvard, Cambridge MA NIH Molecular Libraries Probe Production Centers Network (MLPCN) Grant Number 1R03DA026214-01 Internal Project ID: 2014 Keywords: Streptokinase, inhibition, growth, bacterial, group A streptococcus, virulence Primary Collaborators: Hongmin Sun, University of Missouri-Columbia, sunh@health.missouri.edu Probes: ML126, ML134, ML135 Project Overview: The goal of the project is to identify and develop novel antibiotic small molecules through inhibiting streptokinase (SK) expression in group A streptococcus (GAS). Based on the critical role of SK in GAS pathogenicity, we are attempting to identify chemical compounds that specifically reduce the expression of bacterial SK, without interfering with bacterial viability. Specifically, a probe is a small molecule that shows no less than one hundred fold selection for the primary strain (SKKanGAS, see below) vs a control strain SK(-)GAS (see below) in growth-based assays and shows significant inhibition of SK secretion in abiochemical assay that measure SK activity. The more potent and specific probe will be used to further explore the role of SK in GAS pathogenicity. Primary Assay Summary: Internal Assay ID: 2014-01 Assay: The strain used for this project is a GAS strain carrying the kanamycin resistant gene under the control of the streptokinase promoter (SKKanGAS). Compounds that inhibit streptokinase promoter activity lead to a decrease of the kanamycin resistant gene product and cell death in the presence of kanamycin (Sigma K1637). Briefly, SKKanGAS at OD600 equal to 0.015 were plated onto 384-well plates (Corning 3570) and incubated with test compounds (7.5 uM, 0.2%DMSO) in the presence of 40 ug/ml of kanamycin in Todd-Hewitt Broth medium for 6 hours before cell survival is assessed by BacTiterGlo reagent (Promega G8233). Selectivity is determined by comparing growth inhibition between SKKanGAS and another GAS strain, SK(-)GAS where the kanamycin resistant gene is under the control of an SK-independent promoter. Outcome: A decrease in the luminescent signal will identify compounds that either inhibit the SK promoter, or inhibit the cell growth independent of inhibiting the SK promoter. Normalization of the HTS data across runs and calibration to the positive control was performed as described below. The results are reported as % inhibition. Specificity for SK promoter inhibition will be determined in a secondary assay where a GAS strain carrying kanamycin resistant gene which is not controlled by the SK promoter will be used. PubChem AID 1662 Number compounds evaluated: 303545 Active Compounds : Activity_Score >=50 Number of active compounds: 3959 Inconclusive Compounds: Activity_Score < 50 with at least one replicate activity score >=50. Number of inconclusive compounds: 795 Dose Confirmation HTS - AID# 1900 Assay Biology/Type: Cell-Based (SK(-)GAS). Readout Technology: Plate Reader/Luminescence. Target Pathway: Streptokinase (SK) expression. Test concentration(s): 6-point Dose Titration (0.06, 0.18, 0.56, 1.60, 5.00 and 15.00 microM). Activity criterion: EC50 <= 1 log over the highest tested concentration. Number of Substances evaluated: 3229 Number of Substances active: 2881 Dose Confirmation HTS - AID# 1902 Assay Biology/Type: Cell-Based (SKKanGAS). Readout Technology: Plate Reader/Luminescence. Target Pathway: Streptokinase (SK) expression. Test concentration(s): 6-point Dose Titration (0.06, 0.18, 0.56, 1.60, 5.00 and 15.00 microM). Activity criterion: EC50 <= 1 log over the highest tested concentration. Number of Substances evaluated: 3227 Number of Substances active: 2946 Dose Confirmation HTS - AID# 1914 Assay Biology/Type: Cell-Based (GAS UMAA2166). Readout Technology: Plate Reader/Luminescence. Target Pathway: Streptokinase (SK) expression. Test concentration(s): 6-point Dose Titration (0.06, 0.18, 0.56, 1.60, 5.00 and 15.00 microM). Activity criterion: EC50 <= 1 log over the highest tested concentration.# Number of Substances evaluated: 3266 Number of Substances active: 774 Dose Confirmation HTS - AID# 1915 Assay Biology/Type: Cell-Based (GAS UMAA2166). Readout Technology: Plate Reader/Luminescence. Target Pathway: Streptokinase (SK) expression. Test concentration(s): 6-point Dose Titration (0.06, 0.18, 0.56, 1.60, 5.00 and 15.00 microM). Activity criterion: EC50 <= 1 log over the highest tested concentration. Number of Substances evaluated: 3266 Number of Substances active: 2220 Comment The following compounds [SID] were purchased or synthesized for this project: 85281113 85281114 85281115 85281116 85281117 85281118 85281119 85281120 85281121 85281122 85281123 85281124 85281125 85281126 85281127 85281128 85281129 85281130 85281131 85281133 85281134 85281136 85281137 85281138 85281139 85281140 85281141 85281143 85281144 85281145 85281146 85281147 85281148 85281149 85281150 85281152 85281153 85281155 85281157 85281158 85281159 85281161 85281163 85281168 85281169 85281170 85281173 85281174 85281175 87334020 87334021 87334023 87334024 87334025 87334026 87334027 87334028 87334029 87334030 87334031 87334032 85281132 85281135 85281142 85281148 85281151 85281154 85281156 85281160 85281162 85281164 85281165 85281166 85281167 85281171 85281172 Result Definitions
Additional Information Grant Number: 1R03DA026214-01 Data Table (Concise)
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