Disease relevance of isomerase

• Baculovirus expression of two protein disulphide isomerase isoforms from Caenorhabditis elegans and characterization of prolyl 4-hydroxylases containing one of these polypeptides as their beta subunit [1].

High impact information on isomerase

• This enzyme is required for the proper maintenance of post-embryonic body shape in strains with a weakened cuticle, perhaps through ECM stabilization via cross-linking activity, disulfide isomerase protein folding activity, protein disulfide isomerase chaperone activity, or via multifunctional events [2].
• The peptidyl-prolyl isomerase activity of CYP-3 has been characterized against the substrate N-succinyl-Ala-Ala-Pro-Phe-p-nitroanilide, and gives a k(cat)/K(m) value of 2.4 x 10(6) M(-1) s(-1) [3].
• Cyclophilin is identical with peptidylprolyl cis-trans isomerase (PPI; EC 5.2.1.8), an enzyme which catalyses the isomerization between the two proline conformations in proteins, thereby acting as a catalyst in protein-folding events [4].
• Screening of cDNA libraries with polyclonal antibodies raised against L4Pepst and AdPepst showed that a protein disulphide isomerase (Ost-PDI2) was present in both antigen fractions [5].
• This cDNA contains a single, long open reading frame that encodes sequence motifs identical to the two known active sites of PDI for isomerase activity [6].

Associations of isomerase with chemical compounds

• Thus 25-azacoprostane hydrochloride inhibited both a delta 24-sterol reductase and a delta 7-sterol isomerase in C. elegans [7].
• The recombinant protein possessed the typical cis-trans peptidyl-prolyl isomerase activity of cyclophilins and this activity was inhibited by the immunosuppressant cyclosporin A [8].
• Analysis of known protein disulphide isomerase and thioredoxin sequences has revealed the presence of conserved Cys, His and Asp residues required for transglutaminases to catalyze the incorporation of primary amines into protein-bound glutamine residues [9].

Other interactions of isomerase

• Transglutaminases, thioredoxins and protein disulphide isomerase: diverse enzymes with a common goal of cross-linking proteins in lower organisms [10].

References