Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P00790 (PGA)
 2,475 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The interactions of type VI collagen have been investigated, using solid phase binding assays, with two components of the fibrillin-containing microfibrils, the elastin-binding protein, MAGP-1 and its structural relative MAGP-2. Both native and pepsin-treated forms of type VI collagen specifically bound to MAGP-1 but not to MAGP-2. Pepsin type VI collagen was shown to block the binding of MAGP-1 to native type VI collagen indicating that the major MAGP-1-binding site was in the triple-helical region of the molecule. MAGP-1 was found not to bind to collagens I, III, and V. Affinity blotting of pepsin-treated type VI collagen showed that MAGP-1 binding was specific for the collagenous domain of the alpha3(VI) chain. Decorin and biglycan were found not to inhibit the interaction of pepsin-treated type VI collagen with MAGP-1, indicating that its binding site on the collagen is not close to that for the proteoglycans. Reduction and alkylation of disulfide bonds in MAGP-1 did not destroy its type VI collagen-binding properties, indicating that the binding site was likely to be in the cysteine-free, N-terminal domain of MAGP-1. Interestingly, the interaction of MAGP-1 with type VI collagen was inhibited by tropoelastin, suggesting that the binding sites for tropoelastin and type VI collagen may be in the same domain of MAGP-1. A peptide, corresponding to amino acids 29-38 of MAGP-1, was found to inhibit the interactions of MAGP-1 with type VI collagen and tropoelastin. The results suggest that the peptide may contain the binding sequences for both type VI collagen and tropoelastin, and thus that these two proteins may share the same binding site on MAGP-1. The interactions of MAGP-1 with type VI collagen and tropoelastin were both determined to be of moderately high affinity, with Kd values of 5.6 x 10(-7) M and 2.6 x 10(-7) M, respectively. The findings indicate that MAGP-1 may mediate a molecular interaction between type VI collagen microfibrils and fibrillin-containing microfibrils, structures which are often found in close proximity to each other in a wide range of extracellular matrices.
 ...
PMID:Microfibril-associated glycoprotein-1 (MAGP-1) binds to the pepsin-resistant domain of the alpha3(VI) chain of type VI collagen. 927 43

Morphology and compliance of tissue-engineered blood vessels (TEBV) are dependent on the culture period and production of extracellular matrix (ECM) components in order to increase the strength of the developing tissue. The aim of the present study was to evaluate the potential of TEBVs to produce an ECM similar to native arteries and veins. Human smooth muscle cells (SMC) were seeded onto the poly(glycolic acid) (PGA) scaffold and placed in bioreactors filled with DMEM supplemented with growth factors. After 6 weeks, the vessels were harvested from the bioreactors and seeded with human endothelial cells at the lumen for another 3 days. Then, the TEBVs were harvested for RNA and protein isolation for further RT-PCR and Western blot. TEBVs had a similar macroscopic appearance to that of native vessels with no visible evidence of the original PGA. Histological and immunohistochemical analyses indicated the presence of high cell density and development of a highly organized structure of ECM. After 6 weeks of culture, there were significantly lower gene expression of SMC-specific markers, such as alpha-actin, caldesmon, and vimentin, and proteoglycans, such as biglycan, decorin, and versican, and other ECM components, such as collagen I and elastin, in TEBVs, with and without pulsatile conditions, compared to that of native arteries. Gene expression of fibronectin was significantly lower in TEBVs grown during pulsatile conditions compared to that of native arteries. No difference was observed in TEBVs grown during non-pulsatile conditions. The presence of alpha-actin, collagen I, decorin, and fibronectin at protein level was demonstrated in TEBVs with and without pulsatile conditions after 6 weeks and in native veins and arteries as well. How this deviation translates into mechanical properties remains to be explored.
 ...
PMID:Production of extracellular matrix components in tissue-engineered blood vessels. 1667 96