Synergetic Inhibition Effects of Methioninase and Cisplatin against the Growth of Human Lung Adenocarcinoma Cell Line GLC / 昆明医科大学学报

Objective To purify recombinant methioninase and investigate the synergetic inhibitory effect of methioninase and cisplatin on the proliferation of human lung adenocarcinoma cell line GLC. Methods Recombinant methioninase was purified with GST-column from supernatant after ultrasonic disruption of cultured Escherichia coli in the prokaryotic expression system pGEX-4T-1-Met/Dh5a. MTT assay was used to determine the inhibition rate of methioninase in combined with cisplatin on cell proliferation,and their synergistic effect was evaluated by using the q value judge method. Results The concentration of recombinant methionine cleaving enzyme was 0.22 mg/mL, the purity was 95%, and the activity was 0.568 IU/mg. After 72 h culturing, the inhibition rate of cisplatin methionine was 24.80%and 27.49%respectively,while the inhibition rate of the combined drugs was 66.80% ( =1.47>1.15) which showed a significant synergistic effect. Conclusion Both methioninase and cisplatin have the inhibition effect,and the combined drugs display a significant synergistic effect on the proliferation of GLC.

High expression of the L-Methionine ?-lyase gene in E. coli / 医学研究生学报

Objective: To identify and highly express the L-Methionine ?-lyase gene from Trichomonas vaginalis(TVMGL).Methods: The TVMGL gene was cloned into pGEX 4T-2,the recombinant protein expressed in E.coli DH5?and confirmed by SDS-PAGE.Results: Denaturing SDS-PAGE analysis confirmed the predicted size of the fusion protein(GST-TVMGL,68 000) and showed high purity after subsequent affinity chromatography on Glutathione sepharose 4B.The target proteins amounted to 34% of the total bacteria proteins.Conclusion: The L-Methionine ?-lyase gene was highly expressed in E.coli.

Cloning of L-Methionine ?-lyase gene / 医学研究生学报

Objective:To identify,clone,sequence the L-Methionine ?-lyase gene from Trichomonas vaginalis(TVMGL1).Methods:Total RNA was prepared from primitive protozoon trichomonas vaginalis,cDNA fragment encoding Methionine ?-lyase gene was amplified by RT-PCR using specific primers,and then was cloned into pGEM-T vector.Inserted Methionine ?-lyase gene was sequenced by ABI 3730 DNA Sequencer.Results:Analysis indicates that the DNA fragment is 1 191 base pairs in length and has high nucleotide homology with that reported previously.Conclusion:L-Methionine ?-lyase gene was successfully cloned.