This observation raises a question regarding the biological significance of two apparently similar enzymes present in the same cellular compartment: do they interact with different substrates or do they catalyse different reactions?
To characterize the interaction between model peptides and the periplasmic PPIase Ppi D from E.
coli, we employed a chemical crosslinking strategy that has been used previously to elucidate the interaction of substrates with Sur A.
In total, there are now 18 PDI-family members in the human endoplasmic reticulum, with different domain architectures and active site chemistries.
To understand why multicellular organisms express multiple proteins with similarity to the archetypal mammalian PDI, the properties of three PDIs from the nematode C.elegans were investigated.
Post-translational limitations in the endoplasmic reticulum during recombinant monoclonal antibody production are an important factor in lowering the capacity for synthesis and secretion of correctly folded proteins.
Mammalian protein disulfide isomerase (PDI) has previously been shown to have a role in the formation of disulfide bonds in immunoglobulins.
Therefore, C elegans has the potential to provide an insight into how pathogenic nematodes survive and proliferate in these environments.
We found that C elegans can maintain over 90% survival in p H conditions ranging from p H 3 to 10.
This was unrelated to the non-specific protection provided by the cuticle.
Global transcriptional analysis identified many genes, which were differentially regulated by p H.
Several attempts have been made to improve the rate of recombinant protein production by overexpressing PDI but the results from these studies have been inconclusive.