Figure - PMC

Skip to main content

An official website of the United States government

Here's how you know

Here's how you know

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

View full-text article in PMC

. 2020 Aug 4;11:1728. doi: 10.3389/fimmu.2020.01728

Search in PMC
Search in PubMed
View in NLM Catalog
Add to search

Copyright © 2020 Haque, Cortes, Alam, Sreedhar, Ferreira and Pangburn.

This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

PMC Copyright notice

Measurement of the affinity between C3b and the three C3b binding sites of Factor H. Each data point represents the equilibrium saturation level from one individual ligand binding curve from experiments like those described in Figure 3. (A) rH 1-6 bound to the Ni-NTA chip exhibited the highest affinity and required C3b concentrations from 0.014 to 0.88 μM to approach saturation. The K_d was determined by fitting the data using non-linear regression to a single site ligand binding equation (Bound = (Capacity^*[Free])/(K_d + [Free])) using GraFit 5 program (Erithacus). C3b was dialyzed into HBS-P. (B) Same as (A), except purified rH 19-20 was attached to the Ni-NTA surface, (C) Same as (A), except purified rH 6-15 was attached to the Ni-NTA surface. Higher concentrations of C3b were required in (B,C) due to the lower affinity of these proteins for C3b.