Expression of two novel recombinant proteins from aortic adventitia (kappafibs) sharing amino acid sequences with cytomegalovirus.

Abstract

We have recently purified and partially sequenced a microfibrillar protein from human aortic adventitia (aneurysm-associated antigenic protein, 40 kDa [AAAP-40]) that is immunoreactive with immunoglobulin (IgG) from the wall of abdominal aortic aneurysms (AAAs). It shares motifs with Ig kappa (which may act as a binding site for interaction with integrins), cytomegalovirus (which may be a molecular mimic in the pathogenesis of AAA), and vitronectin and the fibrinogens. A cDNA library was constructed from the aortic adventitia of a AAA. The library was screened with either rabbit anti-vitronectin antibody or rabbit anti-fibrinogen antibody. Positive plaques were purified and expressed in a strain of Escherichia coli. The clone sequences were analyzed. The expressed proteins were separated by SDS/PAGE and the immunoblots were probed with either AAA IgG or anti-human Ig kappa antibody. Experimental cell lines, transfected with the clones (clones 1 and 5), synthesized recombinant proteins (rAAAP-CL1 and rAAAP-CL5), detectable in Western immunoblots with AAA IgG. A prediction of the tertiary structure resembles well-characterized cell adhesion molecules. These findings suggest that there is a novel family of matrix proteins that may use immunoglobulin motifs as binding sites for cellular integrins and that there are matrix proteins in addition to AAAP-40 that may serve as autoantigens in the pathogenesis of AAA disease.

• Authors: K J Ozsvath, H Hirose, S Xia, D Chew, J Knoetgen 3rd, M D Tilson
• Journal: The Journal of surgical research (J Surg Res) Vol. 69 Issue 2 Pg. 277-82 (May 1997) ISSN: 0022-4804 [Print] United States
• PMID: 9224393 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Autoantigens
• Cell Adhesion Molecules
• Contractile Proteins
• Extracellular Matrix Proteins
• Immunoglobulin kappa-Chains
• Immunoglobulins
• RNA Splicing Factors
• Viral Proteins
• microfibrillar protein

Topics

• Amino Acid Sequence
• Aorta (chemistry)
• Aortic Aneurysm (metabolism)
• Autoantigens (genetics)
• Cell Adhesion Molecules (genetics)
• Contractile Proteins (genetics)
• Cytomegalovirus (chemistry)
• Extracellular Matrix Proteins (genetics)
• Humans
• Immunoglobulin kappa-Chains (chemistry)
• Immunoglobulins (chemistry)
• Models, Molecular
• Molecular Sequence Data
• Phylogeny
• Protein Structure, Tertiary
• RNA Splicing Factors
• Sequence Alignment
• Viral Proteins (chemistry)