Expression of scFv-anti-CHIKV-E2 in Escherichia coli with chaperones Co-expression, and its functional assay by electrochemical immunosensor

ABSTRACT

Single Chain Variable Fragment (scFv), a small fragment of antibody can be used to substitute the monoclonal antibody for diagnostic purposes. Production of scFv in Escherichia coli host has been a challenge due to the potential miss-folding and formation of inclusion bodies. This study aimed to express anti-CHIKV E2 scFv which previously designed specifically for Asian strains by co-expression of three chaperones that play a role in increasing protein solubility; GroEL, GroES, and Trigger Factor. The scFv and chaperones were expressed in Origami B E. coli host under the control of the T7 promoter, and purified using a Ni-NTA column. Functional assay of anti-CHIKV-E2 scFv was examined by electrochemical immunosensor using gold modified Screen Printed Carbon Electrode (SPCE), and characterized by differential pulses voltammetry (DPV) using K3[Fe(CN)6] redox system and scanning microscope electron (SEM). The experimental condition was optimized using the Box-Behnken design. The results showed that co-expression of chaperone increased the soluble scFv yield from 54.405 μg/mL to 220.097 µg/mL (~5×). Furthermore, scFv can be used to detect CHIKV-E2 in immunosensor electrochemistry with a detection limit of 0.74048 ng/mL and a quantification limit of 2,24388 ng/mL. Thus, the scFv-anti-CHIKV-E2 can be applied as a bioreceptor in another immunoassay method.

KEYWORDS:

• scFv-anti-CHIKV-E2
• chaperonesco-expression
• gold modified SPCE
• electrochemical immunosensor

Acknowledgments

We would like to acknowledge the financial support provided for this research by Padjadjaran University, Indonesia under the internal grant (HIU RKDU 2203/UN6.3.1/PT.00/2022). We extend our appreciation to Syifa Tazkia and Salma Nur Zakiyyah for their valuable contributions in experimenting.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The data that support the findings of this study are available from the corresponding author, [SG], upon reasonable request.

Informed consent statement

This research did not involve human subject or part of human or animal. Therefore, the ethical approval is not applicable.

Author contribution

Conceptualization, SG., and TS; methodology, SHN, and YWH; software, SI; validation, SG., and MTN; formal analysis, SG. and MY; investigation, SHN, and YWH; resources, SG and TS.; data curation, SG. and MY; writing-original draft preparation, SG; writing – review and editing, SG, SHN, and SI; visualization, YWH, and SHN; supervision, SG, SI, and YWH; project administration, SG and YWH; funding acquisition, SG.

Additional information

Funding

The work was supported by the Universitas Padjadjaran [2203/UN6.3.1/PT.00/2022].