Pochonia chlamydosporia - Biological Engineering
Transcription
Pochonia chlamydosporia - Biological Engineering
Identification and Determination of nucleotides involved in the process of Biosynthesis of Radicicol from Pochonia chlamydosporia Jia Zeng, Arumon Mukherjee Biological and Irrigation Engineering Department, Utah State University Contact: [email protected] Introduction Fungal polyketides sharing the resorcylic acid lactone (RAL) scaffold display an impressive array of biological activities. Radicicol, one of the fungal polyketides, is produced by Pochonia chlamydosporia. It inhibits the Hsp90 molecular chaperone, another important target for cancer chemotherapy. Recently, gene clusters for biosynthesis of radicicol from Pochonia chlamydosporia were sequenced. However, the function of each enzyme is still waiting for be analyzed, which would interprets the mechanism of radicicol synthesis process. One of the significant differences between fungal and bacteria genes is that the introns exist in the genomic DNA of fungi. When heterologously expressed in E.coli cells, we must remove the introns which can not be recognized by prokaryote. Therefore, Synthesize the cDNA from mRNA is an effective method. In order to identify the concentration and purity of mRNA and cDNA, NanoDrop is involved in this experiment. Experimental Procedure 7kb Strains and culture condition: Pochonia chlamydosporia was obtained from Agricultural Research Service Culture Collection of USDA and was maintained on Difco potato dextrose broth (PDB) media. Incubated it at 28℃ for 4 days. mRNA extraction: mRNA was isolated from P. chlamydosporia grown for 4 days in PDB media using a RNeasy Plant Mini Kit (Qiagen). 1. Extract the mRNA and reverse-trasnlate to cDNA from P. chlamydosporia. 2. Determine the concentration and purity of mRNA and DNA samples.. 3. Clone the functtional genes by PCR. cDNA cloning: SuperScript. III FirstStrand Synthesis System for RT-PCR Kit (invitrogen) was used for reverse transcription and synthesize the cDNA from mRNA. sample 1: the mRNA extracted from P. chlamydosporia. sample 2: Purified mRNA by adding DNAase to remeove the remaining genomic DNA sample 3: cDNA Reverse-Translated from mRNA. sample 4: PCR product of rdc1 genes, Using cDNA as template sample 5: Bovine Serum Albumin (BSA) as protein comparison group TM NanoDrop Sample measurement = 0.5 – 2.0 ul We managed to clone those related functional genes from cDNA of P.chlamydosporia which were reverse-translated from mRNA. Using NanoDrop, we tested the purity and determined the concentration of the extracted mRNA and reverse-translated cDNA, by comparing the results of UV absorption. The mRNA and cDNA can be used for the further research such as PCR and protein expression in the future. Future Work 2. Research on the property of the kinetic chacractors High accuracy and high reproducibility Results and Discussion . Patented sample retention technology between two optical fibres Sample ID Concentration A260 A280 260/280 Principle: Sample 1 154.47 ng/ul 3.089 1.489 2.07 A= ε * b * c Sample 2 104.55 ng/ul 2.091 1.055 1.98 A = absorbance (A) Sample 3 866.89 ng/ul 17.338 10.611 1.63 ε = Molar absorptivity coefficient (liter/mol-cm) Sample 4 24.87 ng/ul 0.497 0.288 1.73 Sample 5 4.92 mg/ml - - 0.68 c = Analyte concentration (moles/liter or molarity) Radicicol 1. Express rdc genes in E.coli cells. NanoDropTM 1000 b = Pathlength (cm) The compounds in P. chlamydosporia check by HPLC supernatant Conclusions Identify all the above 5 samples and determine their concentration by NanoDrop. Beer-Lambert equation The PCR result of rdc1 mycelia Identification and determination by NanoDrop: Objectives Results and Discussion Table represents the different concentrations and purity of the samples 1 – 5 using NanoDrop. Every sample was tested twice and the mean value was taken. It is clear that Sample 1 consisted of a mixture of mRNA and g-DNA. After further purification by adding DNAase, the result showed that Sample 2 consisted of pure mRNA giving a 260/280 ratio of 1.98. From Sample 2, we reversetranslate it to cDNA, giving a 260/280 ratio of 1.63. The cDNA from Sample 3 was used as a template for PCR cloning. This gene is our Sample 4, which is a pure DNA. Lastly, after recalibrating the NanoDrop, we measured the purity of Bovine Serum Albumin. of rdc genes in vitro. 3. Synthesize different active compounds by different combination of enzymes. Acknowledgement 1. We are very thankful to Dr. Jixun Zhan for providing the strain and extraction kit. 2. We are also very thankful to Dr. Charlie Miller for providing us the NanoDropTM.