TY - JOUR
T1 - Humanized recombinant vaccinia virus complement control protein (hrVCP) with three amino acid changes, H98Y, E102K, and E120K creating an additional putative heparin binding site, is 100-fold more active than rVCP in blocking both classical and alternative complement pathways
AU - Ghebremariam, Yohannes T.
AU - Odunuga, Odutayo O.
AU - Janse, Kristen
AU - Kotwal, Girish J.
PY - 2005
Y1 - 2005
N2 - Vaccinia virus complement control protein (VCP) is able to modulate the host complement system by regulating both pathways of complement activation. Efficient downregulation of complement activation depends on the ability of the regulatory protein to effectively bind the activated third (C3b) and fourth (C4b) complement components. Based on native crystallographic structure, molecular modeling, and sequence alignment with other Orthopoxviral complement control proteins (CCPs) and their host homologs, putative sites have been found on VCP as contact points for C3b/C4b. Here, we report that using site-directed mutagenesis, modified proteins have been generated. In addition, we report that the generated modified proteins with postulated contact point substitutions have shown greater ability to regulate both the classical and the alternative pathways of complement activation than the recombinant Western Reserve VCP, with one modified protein showing nearly 100-fold more potency in regulating both complement activation pathways independently. The augmented in vitro inhibitory activity of the modified protein together with the newly created putative heparin binding site suggests its promising potential as a competent therapeutic agent in modulating various complement-mediated ailments, for example, traumatic brain injury, Alzheimer's disease, rheumatoid arthritis, multiple organ dysfunction syndrome, reperfusion injury, and xenorejection.
AB - Vaccinia virus complement control protein (VCP) is able to modulate the host complement system by regulating both pathways of complement activation. Efficient downregulation of complement activation depends on the ability of the regulatory protein to effectively bind the activated third (C3b) and fourth (C4b) complement components. Based on native crystallographic structure, molecular modeling, and sequence alignment with other Orthopoxviral complement control proteins (CCPs) and their host homologs, putative sites have been found on VCP as contact points for C3b/C4b. Here, we report that using site-directed mutagenesis, modified proteins have been generated. In addition, we report that the generated modified proteins with postulated contact point substitutions have shown greater ability to regulate both the classical and the alternative pathways of complement activation than the recombinant Western Reserve VCP, with one modified protein showing nearly 100-fold more potency in regulating both complement activation pathways independently. The augmented in vitro inhibitory activity of the modified protein together with the newly created putative heparin binding site suggests its promising potential as a competent therapeutic agent in modulating various complement-mediated ailments, for example, traumatic brain injury, Alzheimer's disease, rheumatoid arthritis, multiple organ dysfunction syndrome, reperfusion injury, and xenorejection.
KW - 100-Fold potency
KW - Complement
KW - Heparin
KW - Humanized rVCPs
KW - Site-directed mutagenesis
KW - rVCP
UR - http://www.scopus.com/inward/record.url?scp=29744456997&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=29744456997&partnerID=8YFLogxK
U2 - 10.1196/annals.1352.024
DO - 10.1196/annals.1352.024
M3 - Article
C2 - 16387681
AN - SCOPUS:29744456997
SN - 0077-8923
VL - 1056
SP - 113
EP - 122
JO - Annals of the New York Academy of Sciences
JF - Annals of the New York Academy of Sciences
ER -