Comparing the expression of human DNA topoisomerase I in KM71H and X33 strains of Pichia pastoris

Ruo, Ping Ang and Leong, Sin Teoh and Mooi, Kwai Chana and Miswan, Noorizan and Boon, Yin Khoo (2016) Comparing the expression of human DNA topoisomerase I in KM71H and X33 strains of Pichia pastoris. Electronic Journal of Biotechnology, 21. pp. 9-17. ISSN 0717-3458

Full text not available from this repository.


Human is an essential cellular enzymethat is found in all human cells. As this enzyme is upregulated in cancer cells exceedingly, it is used as a target for cancer chemotherapeutic drug development. As such, producing the in-house enzyme for the purpose to speed up the search for more cost-effective and target specific hTopoI inhibitors is warranted. This study aims to compare the optimised conditions for the expression of hTopoI in KM71H (MutS) and X33 (Mut+) strains of Pichia pastoris. P. pastoris transfected with an hTopoI recombinant vector was used for the optimization of a higher level of hTopoI expression. Results: In the process, fed-batch cultivation parameters that influence the expression of hTopoI, such as culture temperature, methanol induction and feeding strategy, were optimised in the transfected KM71H and X33 P. pastoris strains in a shake flask system. The cell density and total protein concentration (protein level) of transfected P. pastoris were compared to determine the optimum culture conditions for each transfected P. pastoris strain. A higher hTopoI level was observed in the transfected KM71H culture supernatant (2.26 ng/mL) when the culture was incubated in the optimum conditions. Conclusions: This study demonstrated thatMutS strain (KM71H) expressed and secreted a higher level of hTopoI heterologous protein in the presence of methanol compared to the Mut+ strain; X33 (0.75 ng/mL). However, other aspects of optimization, such as pH, should also be considered in the future, to obtain the optimum expression level of hTopoI in P. pastoris.

Item Type: Article
Subjects: R Medicine > R Medicine (General) > R735-854 Medical education. Medical schools. Research
T Technology > T Technology (General) > T1-995 Technology(General)
Divisions: Institut Penyelidikan Perubatan Molekul (Institute for Research in Molecular Medicine INFORMM) > Article
Pusat Pengajian Teknologi Industri (School of Industrial Technology) > Article
Depositing User: Mr Noorazilan Noordin
Date Deposited: 29 Sep 2017 07:12
Last Modified: 29 Sep 2017 07:12

Actions (login required)

View Item View Item