scholarly journals Construction of Fluorescent Immunosensor Quenchbody to Detect His-Tagged Recombinant Proteins Produced in Bioprocess

Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 4993
Author(s):  
Xuerao Ning ◽  
Takanobu Yasuda ◽  
Tetsuya Kitaguchi ◽  
Hiroshi Ueda

With the widespread application of recombinant DNA technology, many useful substances are produced by bioprocesses. For the monitoring of the recombinant protein production process, most of the existing technologies are those for the culture environment (pH, O2, etc.). However, the production status of the target protein can only be known after the subsequent separation and purification process. To speed up the monitoring of the production process and screening of the higher-yield target protein variants, here we developed an antibody-based His-tag sensor Quenchbody (Q-body), which can quickly detect the C-terminally His-tagged recombinant protein produced in the culture medium. Compared with single-chain Fv-based Q-body having one dye, the Fab-based Q-body having two dyes showed a higher response. In addition, not only was fluorescence response improved but also detection sensitivity by the mutations of tyrosine to tryptophan in the heavy chain CDR region. Moreover, the effect of the mutations on antigen-binding was successfully validated by molecular docking simulation by CDOCKER. Finally, the constructed Q-body was successfully applied to monitor the amount of anti-SARS CoV-2 nanobody secreted into the Brevibacillus culture media.

2000 ◽  
Vol 66 (11) ◽  
pp. 5024-5029 ◽  
Author(s):  
Luis A. Fernández ◽  
Isabel Sola ◽  
Luis Enjuanes ◽  
Víctor de Lorenzo

ABSTRACT A simple method for the nontoxic, specific, and efficient secretion of active single-chain Fv antibodies (scFvs) into the supernatants ofEscherichia coli cultures is reported. The method is based on the well-characterized hemolysin transport system (Hly) of E. coli that specifically secretes the target protein from the bacterial cytoplasm into the extracellular medium without a periplasmic intermediate. The culture media that accumulate these Hly-secreted scFv's can be used in a variety of immunoassays without purification. In addition, these culture supernatants are stable over long periods of time and can be handled basically as immune sera.


Biochemistry ◽  
1999 ◽  
Vol 38 (2) ◽  
pp. 532-539 ◽  
Author(s):  
Hiroyuki Kobayashi ◽  
Hiroshi Morioka ◽  
Kunihiro Tobisawa ◽  
Takuya Torizawa ◽  
Koichi Kato ◽  
...  

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