Purification and functional characterization of recombinant Balsamin, a ribosomeinactivating protein from Momordica balsamina

Thumbnail Image
Ajji, Parminder K.
Sonkar, Shailendra P.
Walder, Ken
Puri, Munish
Journal Title
Journal ISSN
Volume Title
© 2018 Published by Elsevier B.V.
Rights Holder
Elsevier B.V.
Balsamin, a type I ribosome-inactivating protein (RIP), has been shown to inhibit HIV-1 replication at the translation step. Our recent studies have shown that balsamin also possess anti-tumor, antibacterial and DNase-like activity, however, the amount of natural balsamin in Momordica balsamina seeds is limited and preclinical studies require large quantities of pure, bioactive balsamin. Therefore, in this study, we cloned the balsamin gene, expressed it in E.coli BL21 (DE3) strain and purified it by nickel affinity chromatography. Functional analysis indicated that balsamin exhibits both RNA N-glycosidase activity, releasing the Endo-fragment from rabbit reticulocyte rRNA, and DNase-like activity, converting the supercoiled form of a plasmid into the linear form in a concentration-dependent manner. Analysis of secondary structure revealed that recombinant balsamin mainly consisted of α-helical and random coiled with minimal turns and β-sheets. Recombinant balsamin was found to be stable in the temperature range of 20-60 °C and pH range of 6-9. Antimicrobial assays showed that the minimum inhibitory concentrations of recombinant balsamin for various pathogens ranged between 1.56-12.5 μg/ml. Heterologous expression and purification of balsamin carries great importance as it provides an alternative approach for large-scale preparation of biologically active recombinant balsamin, which is difficult from its natural source.
© 2018 Published by Elsevier B.V. This manuscript version is made available under the CC-BY-NC-ND 4.0 license: http://creativecommons.org/licenses/by-nc-nd/4.0/ This author accepted manuscript is made available following 12 month embargo from date of publication (February 2018) in accordance with the publisher’s archiving policy
bioactive, nutraceutical, RNA N-glycosidase, DNase, antimicrobial and heterologous expression
Ajji, P. K., Sonkar, S. P., Walder, K., & Puri, M. (2018). Purification and functional characterization of recombinant balsamin, a ribosome-inactivating protein from Momordica balsamina. International Journal of Biological Macromolecules, 114, 226–234. https:// doi.org/10.1016/j.ijbiomac.2018.02.114