[Identification of antigenic epitopes of human apurinic/apyrimidinic endonuclease monoclonal antibodies and their application].
OBJECTIVE
To identify the antigenic epitopes of human apurinic/apyrimidinic endonuclease monoclonal antibodies (hAPE1 mAb) and to establish a one-step ELISA for quantitative measurement of hAPE1.


METHODS
APE1-15 polypeptide array was used to identify the antigenic epitopes of hAPE1 mAb. Molsoft. ICM-Pro software was used to display the three dimensions of antigenic epitopes of hAPE1 mAbs. hAPE1 mAb was labeled with HRP by modified method of sodium periodate oxidization. A one-step ELISA was established by using two hAPE1 mAbs as a capture antibody and a detection antibody, respectively.


RESULTS
The antigenic epitopes of 2-G1 mAb were localized within amino acids (aa) 76-90 and 109-123 in APE1 redox domain, belonging to the conformational epitope category. The antigenic epitope of 4-F6 mAb was within aa 109-147 in DNA repair endonuclease domain. In the range of 8.0 microg/L to 200 microg/L, the hAPE1 antigen showed a good linearity in the standard curve. The minimum detection threshold of this assay was 2.0 microg/L. The average of intra-assay precision and inter-assay precision were 8.67% and 12.45%, respectively. The average recovery rate was 105.47%.


CONCLUSIONS
hAPE1 2-G1 mAb and 4-F6 mAb have different antigenic epitopes, and the one-step ELISA is established successfully to detect the serum hAPE1 level easily, quickly and accurately.
Shan
Jin-lu
JL
Cancer Center, Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing, China. lulu7476@sina.com
Dai
Nan
N
Zhang
Qin-hong
QH
Li
Zeng-peng
ZP
Cao
Xiao-jing
XJ
Wang
Dong
D
D000911:Antibodies, Monoclonal / Q000276:immunology*; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D018604:Epitope Mapping; D000939:Epitopes / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D006801:Humans; D008968:Molecular Conformation
D000911:Antibodies, Monoclonal; D000939:Epitopes; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase