COL4A3 Human
Greater than 95.0% as determined by SDS-PAGE.
Description
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.
Product Specs
Type IV collagen, a crucial component of basement membranes, is a multimeric protein formed by three alpha subunits. These subunits are encoded by six genes (alpha 1 to alpha 6). Each alpha subunit can intertwine with two others, creating a triple helix structure that forms type IV collagen. Goodpasture syndrome, an autoimmune disease, is characterized by autoantibodies attacking collagen molecules within the basement membranes of alveoli and glomeruli. These autoantibodies primarily target epitopes found in the non-collagenous C-terminal domain of the protein. The human COL4A3 gene exhibits multiple unique alternative transcripts, with alternative splicing confined to the six exons responsible for encoding the C-terminal domain. Additionally, COL4A3 is implicated in an autosomal recessive form of Alport syndrome, where mutations within the exons encoding the C-terminal region contribute to the disease. This gene is arranged head-to-head with another type IV collagen gene, allowing them to share a common promoter. Notably, several exons of COL4A3 are interspersed with exons of an uncharacterized gene located on the opposite strand.
This product represents the human α3 chain of collagen IV, which is synonymous with the antigen termed 'glomerular basal membrane antigen' (GBM). It serves as a recombinant antigen in both solid-phase (ELISA) and fluid-phase diagnostic assays. Its calculated molecular weight is 53kDa and its calculated isoelectric point is pH 8.9. The product consists of cDNA encoding a minicollagen version of the human collagen IV α3 chain, fused to a hexa-histidine purification tag. The designation 'minicollagen' signifies the removal of a significant portion of the triple-helical collagenous region, located between the N-terminal 7S domain and the C-terminal noncollagenous NC1 domain. This removal is essential for the recombinant production of this antigen.
The product appears as a clear solution that has undergone sterile filtration.
The protein solution is formulated with 20mM Hepes at a pH of 8.0 and 4M Urea.
For optimal storage, a neutral to slightly alkaline pH buffer with 4M urea as a dissociating agent is recommended. Store the product at a temperature between -70°C and -80°C. It is crucial to avoid repeated freeze-thaw cycles.
SDS-PAGE analysis has determined a purity greater than 95.0%.
The recommended coating concentration ranges from 0.12 to 0.5 µg/ml. The optimal concentration may vary based on the specific ELISA plate and coating buffer used. The product is suitable for the labeling of functional groups.
Research suggests that the immunodominant epitope of GBM is a cryptic epitope, meaning it's not readily accessible to its corresponding autoantibodies. To expose these epitopes, it is necessary to treat the protein under non-reducing conditions with a denaturant like urea (for reference, see Hellmark et al. in Autoantibodies, Peter, J.B. and Shoenfeld, Y., eds., Elsevier B.V., 1996, pp 291-298).
This product serves the following immunological functions: (1) It binds to IgG-type human auto-antibodies. (2) It acts as a standard in ELISA tests for checkerboard analysis of positive and negative samples. (3) It's utilized in immunodot tests with positive and negative samples.
Product Science Overview
Collagen Type IV is unique among collagens because it forms a network rather than fibrils. The alpha-3 chain of Collagen Type IV combines with alpha-4 and alpha-5 chains to form a triple-helical structure, which is essential for the stability and function of the basement membrane . This network provides structural support and plays a role in filtration processes in the kidneys.
The human recombinant form of Collagen Type IV Alpha 3 is produced using advanced biotechnological methods. Typically, the cDNA coding for the alpha-3 chain is inserted into an expression system, such as insect cells (Sf9), to produce the protein . The recombinant protein is then purified to a high degree of purity, often greater than 95%, and formulated for various applications .
Recombinant Collagen Type IV Alpha 3 is used in various research and diagnostic applications. It is particularly useful in enzyme-linked immunosorbent assays (ELISA) for detecting autoantibodies associated with Goodpasture syndrome, a condition where the immune system mistakenly attacks the basement membranes in the kidneys and lungs . The protein can also be used in studies related to Alport syndrome, an inherited disorder affecting the kidneys .
Mutations in the COL4A3 gene are linked to several diseases, including Alport syndrome and Goodpasture syndrome . In Alport syndrome, mutations disrupt the normal function of the glomerular basement membrane, leading to progressive kidney disease . In Goodpasture syndrome, the immune system targets the alpha-3 chain, causing inflammation and damage to the kidneys and lungs .
