Table 1

Library and primer sequences"

Fig. 1

Identification of recombinant plasmid digestion M. 5 000 bp DNA marker; the other lanes showed the enzyme digestion results of different recombinant plasmids"

Fig. 2

Soluble identification of recombinant proteins with different tags M. Protein marker; the different labels above the horizontal line correspond to different tag recombinant proteins; 1. Before induction; 2. After induction; 3. Supernatant after sonication; 4. Precipitation after sonication; red box marking the expression of recombinant proteins in the supernatant"

Fig. 3

Purification and Western blot detection of target protein A. Protein purification of the recombinant rMBP-S1 (M. Protein marker; 1. Before induction; 2. After induction; 3. Supernatant after sonication; 4. Precipitation after sonication; 5, 6. 20 mmol·L-1 imidazole washed twice; 7, 8. 50 mmol·L-1 imidazole washed twice; 9, 10. 250 mmol·L-1 imidazole eluted twice; 11. Protein after ultrafiltration; red box marked the target protein); B. Western blot identifies the recombinant rMBP-S1 and rMBP, arrows indicate the recombinant proteins rMBP-S1 and rMBP"

Fig. 4

IFA detected the biological activity of recombinant protein rMBP-S1 After 1 h incubation of different recombinant proteins for 4 ℃, IFA was performed, DMEM 4 ℃ was incubated for 1 h as a blank control group, and the binding to cells was observed by laser confocal microscopy, Dil staining the cell membrane (red), DAPI staining the nucleus (blue)"

Table 2

The optimal number of cycles in each round"

Fig. 5

Enrichment was monitored by qPCR (A) and flow cytometry (B) A. Round 3 (light green), 7 (orange), 11 (blue) and 15 (red) input screening library melting curve, NC (dark green) for the initial random library control, the higher the melting chain temperature, the single enrichment degree higher; B. Rounds of input screening library incubation with target protein detection using flow cytometry. NC (dark green) for the initial random library control, with screening, fluorescence right shift, can combine with the target sequence, the higher the degree of enrichment"

Table 3

Candidate aptamer sequences"

Fig. 6

Affinity, specificity analysis of aptamer A. S1-3 aptamer affinity analysis; B. S1-11 aptamer affinity analysis; C. S1-3 aptamer specificity analysis"

Fig. 7

Prediction of secondary structure of aptamer Apt-S1-3 and molecular docking with the overall structure of target protein rMBP-S1 A. Secondary structure prediction results of aptamer Apt-S1-3;B. Molecular docking results of aptamer Apt-S1-3 (orange) and the overall structure of target protein rMBP-S1 (cyan)"

Fig. 8

IFA validation of virus recognition by the aptamer"

Fig. 9

The effect of the aptamer Apt-S1-3 on PEDV-GFP virus infection A. Fluorescence microscopy observation; B. Flow cytometry detection. *. P < 0.05; **. P < 0.01; ***. P < 0.001; ****. P < 0.000 1"