Human α3 chain of collagen IV; identical with the antigen called "glomerular basal membrane antigen" (GBM). Recombinant antigen for solid (ELISA) and fluid phase diagnostic assays. Calculated Molecular weight: 53kDa. Calculated isoelectric point: pH 8.9.
cDNA coding for a minicollagen version of the human collagen IV α3 chain fused to a hexa-histidine purification tag. The term minicollagen designates the removal of most of the epitope-less triplehelical collagenous region (situated between the N-terminal 7S domain and the C-terminal noncollagenous NC1 domain), which is a requirement for recombinant production of this antigen.
The protein solution contains 20mM Hepes, pH 8.0 and 4M Urea.
Recommendations for storage buffer: neutral to slightly alkaline pH and 4M urea as dissociating agent.
Storage temperature: -70°C to -80°C.
Please prevent freeze-thaw cycles.
Greater than 95.0% as determined by SDS-PAGE.
0.12-0.5 μg/ml (depending on the type of ELISA plate and coating buffer). Suitable for labeling of functional groups.
It has been reported that the immunodominant epitope of GBM is a cryptic epitope that is not easily accessible to the corresponding autoantibodies. It is necessary to treat the protein under nonreducing conditions with a denaturant such as urea to unmask the epitopes (see Hellmark et al. in Autoantibodies, Peter, J.B. and Shoenfeld, Y., eds., Elsevier B.V., 1996, pp 291-298).
1. Binds IgG-type human auto-antibodies.
2. Standard ELISA test (checkerboard analysis of positive/negative samples.
3. Immunodot test with positive/negative samples.