PubMed Health⌕ Search

Biomedical subjects

Sara Fuchs

Publications and source records attributed to Sara Fuchs.

21 records · Page 2Linked to original sources

Protective molecular mimicry in experimental myasthenia gravis.

Protein databases were searched for microbial sequences that bear amino acid similarities with identified T- or B-cell epitopes within the human alpha-subunit of acetylcholine receptor (AChR). One peptide, derived from Haemophilus influenzae, exhibits 50% homology to an identified T-cell epitope of AChR alpha-subunit. This peptide was shown to have a protective effect in experimental autoimmune myasthenia gravis (EAMG). Pretreatment of rats with the mimicry peptide attenuated the induction and progression of EAMG. These effects were accompanied by a reduced T-cell response to AChR, diminished IL-2, IL-12, IFN-gamma and IL-4 levels, as well as decreased humoral response to self-AChR.

Amino Acid Sequence↗

Coupling of dopamine receptors to G proteins: studies with chimeric D2/D3 dopamine receptors.

D2 and D3 dopamine receptors belong to the superfamily of G protein-coupled receptors; they share a high degree of homology and are structurally similar. However, they differ from each other in their second messenger coupling properties. Previously, we have studied the differential coupling of these receptors to G proteins and found that while D2 receptor couples only to inhibitory G proteins, D3 receptor couples also to a stimulatory G protein, Gs. We aimed to investigate the molecular basis of these differences and to determine which domains in the receptor control its coupling to G proteins. For this purpose four chimeras were constructed, each composed of different segments of the original D2 and D3 receptors. We have demonstrated that chimeras with a third cytoplasmic loop of D2 receptor couple to Gi protein in a pattern characteristic of D2 receptor. On the other hand chimeras containing a third cytoplasmic loop of D3 receptor have coupling characteristics like those of D3 receptor, and they couple also to Gs protein. These findings demonstrate that the third cytoplasmic loop determines and accounts for the coupling of dopamine receptors D2 and D3 to G proteins.

1-Methyl-3-isobutylxanthine↗

Rat interleukin-18 binding protein: cloning, expression, and characterization.

Interleukin-18 binding protein (IL-18BP) is a constitutively expressed and secreted protein that lacks a transmembrane domain. IL-18BP binds specifically to mature IL-18 and inhibits its activity. To study the immunomodulating role of IL-18BP in models of autoimmune diseases in rats, we cloned and characterized rat IL-18BP. Rat IL-18BP has 193 amino acid residues and is highly homologous to human and mouse IL-18BP. Recombinant rat IL-18BP binds to rat IL-18, reacts with antibodies to human or mouse IL-18BP, and inhibits IL-18-dependent interferon-gamma (IFN-gamma) production in vitro. Thus, rat IL-18BP can be employed to antagonize the proinflammatory responses induced by endogenous IL-18 in rat models of autoimmune diseases.

Amino Acid Sequence↗