Abstract
Knowledge about the mechanism by which some antibodies can block HIV-1 entry is critical to our understanding of their function and may offer new avenues for controlling the adhesion of HIV-1 to the host cells. While much progress has been made, this mechanism remains unclear. Here, atomic force microscopy, isothermal titration calorimetry (ITC), and circular dichroism spectroscopy were used to measure some biophysical characteristics of the interaction of four-domains (D1–D4) membrane protein CD4 with anti-D3 antibody OKT4 and with HIV-1 entry blocking anti-D1 antibody Leu3a. The results showed that at 37°C they bind with similar binding strength, thermodynamics, and kinetics but with different assembly states. Further analyzing the interactions at different temperatures by ITC showed that binding of CD4 with Leu3a is characteristic for specific hydrophobic binding as well as for protein folding while with OKT4 comes from an extensive additional hydration upon binding and charge-related interactions within the binding site. Comparing these characteristics with those of HIV-1 gp120-CD4 interaction revealed that Leu3a binds to CD4 faster than HIV-1 followed by changing local structure of D1 to which HIV-1 binds leading to a prevention of viral entry.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
