Figure 1.

The bivalent BL1.2 V_HH construct outperforms the monovalent BL1.1 construct in binding to F4⁺ ETEC at pH ranges found in the GI of weaned piglets

(A) Schematic representation of the main V_HH constructs used in this study.

(B) Indirect ELISA-based binding analysis of the 6xHis and 3xFLAG tagged monovalent BL1.1 and bivalent BL1.2 constructs to F4⁺ and F18⁺ ETEC compared to a control V_HH (Ctrl) carrying a 6xHis and 3xFLAG tag.

(C) Representative SDS-PAGE showing “in solution” binding assay of the untagged BL1.1, BL1.2, and a control V_HH constructs to F4⁺ ETEC.

(D) Binding of the 6xHis and 3xFLAG tagged BL1.1 and BL1.2 constructs to F4⁺ ETEC immobilized on Maxisorp plates at a pH range from 2.6 to 6.0 analyzed by indirect ELISA. Binding analyses (A–D) were performed in independent biological triplicates. Absorbance values (A and D) are presented as mean ± SD (n > 3). Statistics were based on an unpaired two-tailed Student’s t-test (B and D); ∗, p < 0.05; ∗∗∗, p < 0.001.