Single-molecule biotechnology for protein researches

Cells employ proteins to perform metabolic functions and maintain active physiological state through charge transfer and energy conversion.These processes are carried out in a narrow space precisely and rapidly,which,no doubt,bring great difficulty for their detection and dissection.Fortunately,in recent years,the development and expansion of single-molecule technique in protein research make monitoring the dynamical changes of protein at single-molecule level a reality,which also provides a powerful tool for the further exploration of new phenomena and new mechanisms of life activities.This paper aims to summarize the working principle and essential achievements of single-molecule technique in protein research in recent five years.We focus on not only dissecting the difference of nanopores,atomic force microscope,scanning tunneling microscope,and optical tweezers technique,but also discussing the great significance of these single-molecule techniques in investigating intramolecular and intermolecular interactions,electron transport,and conformational changes.Finally,the opportunities and challenges of the single-molecule technique in protein research are discussed,which provide a new door for single-molecule protein research.

Corrigendum to“Aptamer-based cell-free detection system to detect target protein”[Synth Syst Biotechnol 6(3)(2021)209–215]

The authors regret that following the publication of the original article,the authors noticed that the“Affiliation a”were incorrect.It should be“XMU-China Team,College of Chemistry and Chemical Engineering,Xiamen University,Xiamen,361005,PR China”.

Aptamer-based cell-free detection system to detect target protein

Biomarkers of disease,especially protein,show great potential for diagnosis and prognosis.For detecting a certain protein,a binding assay implementing antibodies is commonly performed.However,antibodies are not thermally stable and may cause false-positive when the sample composition is complicated.In recent years,a functional nucleic acid named aptamer has been used in many biochemical analysis cases,which is commonly selected from random sequence libraries by using the systematic evolution of ligands by exponential enrichment(SELEX)techniques.Compared to antibodies,the aptamer is more thermal stable,easier to be modified,conjugated,and amplified.Herein,an Aptamer-Based Cell-free Detection(ABCD)system was proposed to detect target protein,using epithelial cell adhesion molecule(EpCAM)as an example.We combined the robustness of aptamer in binding specificity with the signal amplification ability of CRISPR-Cas12a′s trans-cleavage activity in the ABCD system.We also demonstrated that the ABCD system could work well to detect target protein in a relatively low limit of detection(50-100 nM),which lay a foundation for the development of portable detection devices.This work highlights the superiority of the ABCD system in detecting target protein with low abundance and offers new enlightenment for future design and development.