His18 promotes H2O2 production in copper-ion mediated hIAPP aggregation.

Aims:  This work aims to investigate the binding capability of certain domains at N terminus of the protein of Lactobacillus plantarum to Caco‐2 cells and to test the usage of affinity chromatography to isolate the human mucus component that interacts with them. Methods and Results:  Recombinant proteins containing the first and both the first and second domains at N terminus of fused to a His tag were constructed and used to bind the Caco‐2 cells. The interacting molecule from human mucus was isolated by affinity chromatography through immobilizing the recombinant proteins onto a Sepharose matrix. It was found both recombinant proteins could block the adhesion of Lact. plantarum to Caco‐2 cells and bind to a human mucus component. Conclusions:  The first and both the first and second domains at N terminus of the protein have the capability to adhere Caco‐2 cells and by affinity chromatography, an interacting UV‐absorbing component from human mucus was isolated. Significance and Impact of the Study:  The protein domains characterized in this study may be displayed on probiotics to promote adhesion, and further characterization of the human mucus component might be helpful to identify host factors required for prolonging probiotics persistence in the gastrointestinal tract.

Nanoparticle-decorated polymer-coated sub-microbubbles (NP-P-coated SMBs), as proved, have shown promising application prospects in ultrasound imaging, magnetic resonance imaging, drug delivery, and so forth. However, the quantitative evaluation of the stability and mechanical properties of single NP-P-coated SMB is absent. Here, we first reported the stiffness and Young’s modulus of single NP-P-coated SMB obtained by the PeakForce mode of atomic force microscopy. Such NP-P-coated SMBs could maintain perfect spherical shapes and have a thinner shell thickness (about 10 nm), as determined by characterization using a transmission electron microscope. Young’s modulus of NP-P-coated SMBs is about 4.6 ± 1.2 GPa, and their stiffness is about 15.0 ± 3.1 N/m. Both modulus and stiffness are obtained from the linear region in the force–deformation curve and are nearly independent of their sizes. These results should be very useful to evaluate their stability, which plays a key role in maintaining the shell drug loading and acoustic capabilities.