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Dr Peter Klappa

Reader in Biochemistry

School of Biosciences

 

Dr Peter Klappa joined the School of Biosciences in 1995. He is a member of the Protein Form and Function Group.

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Also view these in the Kent Academic Repository

Article
Winter, J. et al. (2011). Protein disulfide isomerase isomerizes non-native disulfide bonds in human proinsulin independent of its peptide-binding activity. Protein Science [Online] 20:588-596. Available at: http://dx.doi.org/10.1002/pro.592.
Hayes, N., Smales, C. and Klappa, P. (2009). Protein disulfide isomerase does not control recombinant IgG4 productivity in mammalian cell lines. Biotechnology and Bioengineering [Online] 105:770-779. Available at: http://dx.doi.org/10.1002/bit.22587.
Hall, R. et al. (2008). External pH influences the transcriptional profile of the carbonic anhydrase, CAH-4b in Caenorhabditis elegans. Molecular and Biochemical Parasitology [Online] 161:140-149. Available at: http://dx.doi.org/10.1016/j.molbiopara.2008.06.013.
Stymest, K. and Klappa, P. (2008). The periplasmic peptidyl prolyl cis-trans isomerases PpiD and SurA have partially overlapping substrate specificities. FEBS Journal [Online] 275:3470-3479. Available at: http://dx.doi.org/10.1111/j.1742-4658.2008.06493.x.
Karala, A. et al. (2007). Protein disulfide isomerases from C-elegans are equally efficient at thiol-disulfide exchange in simple peptide-based systems but show differences in reactivity towards protein substrates. Antioxidants and Redox Signaling [Online] 9:1815-1823. Available at: http://dx.doi.org/10.1089/ars.2007.1624 .
Pirneskoski, A. et al. (2004). Molecular characterization of the principal substrate binding site of the ubiquitous folding catalyst protein disulfide isomerase. Journal of Biological Chemistry [Online] 279:10374-10381. Available at: http://dx.doi.org/10.1074/jbc.M312193200.
Klappa, P. et al. (2004). A major fraction of endoplasmic reticulum-located glutathione is present as mixed disulfides with protein. Journal of Biological Chemistry [Online] 279:5257-5262. Available at: http://dx.doi.org/10.1074/jbc.M304951200.
Winter, J. et al. (2002). Catalytic activity and chaperone function of human protein-disulfide isomerase are required for the efficient refolding of proinsulin. Journal of Biological Chemistry [Online] 277:310-317. Available at: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=11694508.
Klappa, P. et al. (2001). The pancreas-specific protein disulphide-isomerase PDIp interacts with a hydroxyaryl group in ligands. Biochemical Journal [Online] 354:553-559. Available at: http://dx.doi.org/10.1042/0264-6021:3540553.
Pirneskoski, A. et al. (2001). Domains b' and a' of protein disulfide isomerase fulfill the minimum requirement for function as a subunit of prolyl 4-hydroxylase. The N-terminal domains a and b enhances this function and can be substituted in part by those of ERp57. Journal of Biological Chemistry [Online] 276:11287-11293. Available at: http://dx.doi.org/10.1074/jbc.M010656200.
Webb, H. et al. (2001). Interaction of the periplasmic peptidylprolyl cis-trans isomerase SurA with model peptides. The N-terminal region of SurA id essential and sufficient for peptide binding. Journal of Biological Chemistry [Online] 276:45622-45627. Available at: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=11546789.
Kramer, B. et al. (2001). Functional Roles and Efficiencies of the Thioredoxin Boxes of Calcium-binding Proteins 1 and 2 in Protein Folding. Biochemical Journal 357:83-95.
Klappa, P. et al. (2000). Mutations that destabilize the a ' domain of human protein-disulfide isomerase indirectly affect peptide binding. Journal of Biological Chemistry [Online] 275:13213-13218. Available at: http://dx.doi.org/10.1074/jbc.275.18.13213.
Ruddock, L., Freedman, R. and Klappa, P. (2000). Specificity in substrate binding by protein folding catalysts: Tyrosine and tryptophan residues are the recognition motifs for the binding of peptides to the pancreas-specific protein disulfide isomerase PDIp. Protein Science 9:758-764.
Review
Freedman, R., Klappa, P. and Ruddock, L. (2002). Protein disulfide isomerases exploit synergy between catalytic and specific binding domains. EMBO Reports [Online] 3:136-140. Available at: http://dx.doi.org/10.1093/embo-reports/kvf035.
Freedman, R., Klappa, P. and Ruddock, L. (2002). Model peptide substrates and ligands in analysis of action of mammalian protein disulfide-isomerase. Methods in Enzymology [Online] 348:342-354. Available at: http://dx.doi.org/10.1016/S0076-6879(02)48653-3.
Showing 16 of 21 total publications in KAR. [See all in KAR]

 

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It has been proposed that the incorrect folding of proteins is the molecular basis of various human diseases, e.g. cystic fibrosis, cancer and Alzheimer's disease. To understand disease-causing alterations in the folding pathway of proteins it is therefore important to investigate how proteins fold in general and why misfolding can occur.

Our interests are mainly focused on protein folding and the role molecular chaperones and folding catalysts play in this process. We are particularly interested in the structure, function and specificity of protein disulphide isomerases (protein folding catalysts that contain thioredoxin-like domains) and peptidyl proly cis-trans isomerases. The techniques we use include peptide synthesis, molecular biology, in-vitro transcription and in-vitro translation in cell free systems, cell culture, chemical cross-linking and immuno-histochemistry

Current Projects:

Interaction of protein disulphide isomerases with substrates

 

Multiplicity of Domain structure

The aim of this project is to characterize in more detail (in-vitro and in-vivo) the interaction between substrates and certain members of the protein disulphide isomerase (PDI) family, specifically PDI, ERp57 and PDIp, since these proteins show a comparable domain architecture.

These results will enable the prediction of substrate specificity and potential regulation of other members of the PDI family, e.g. ERp72 and P5. In collaboration with Dr. Lloyd W. Ruddock, Biocentre Oulu, Finland, mutants of PDI and PDIp are generated and the effect of these mutations on the structure, function and specificity is tested.

The aim of this project is to characterize in more detail (in-vitro and in-vivo) the interaction between substrates and certain members of the protein disulphide isomerase (PDI) family, specifically PDI, ERp57 and PDIp, since these proteins show a comparable domain architecture.

These results will enable the prediction of substrate specificity and potential regulation of other members of the PDI family, e.g. ERp72 and P5. In collaboration with Dr. Lloyd W. Ruddock, Biocentre Oulu, Finland, mutants of PDI and PDIp are generated and the effect of these mutations on the structure, function and specificity is tested.

More about specificity of folding catalysis

 

 

Characterisation of protein disulphide isomerase in C.elegans

Eukaryotic PDI family members

Native disulphide bond formation in the endoplasmic reticulum (ER) of eukaryotes is an important, but as yet poorly understood process. For over thirty years, the process of the formation, reduction and isomerisation of disulphide bonds during the folding pathway of secretory proteins in the ER has been thought to be catalysed by the enzyme protein disulphide isomerase (PDI). During the past decade, several proteins with similarity to PDI have been described in the ER of higher eukaryotes, specifically ERp57, ERp72, ERp5, PDIR and PDIp. All the members of this PDI family have similar active sites with the amino acid sequence -WCXXC- and probably contain similar thioredoxin-like domains. Their activities have not been compared systematically, but they appear to have similar enzymatic properties in vitro.

The question arises why there are different members of this protein family present in the same intracellular compartment, i.e. the ER. One inevitable speculation is that they may differ in substrate specificity, but this has not to date been systematically examined. To address the question of the nature of the interaction between protein disulphide isomerases and their substrates I used chemical cross-linkers which have been shown to be a powerful tool to study interactions between proteins. However, one shortcoming of this technique is that it does not address the question of the in vivo function of these proteins. The aim of the planned research project therefore is to characterise the in vivo function of members of the PDI family, specifically PDI, ERp57, ERp72 and ERp5 by using C.elegans as a model organism. EST-analysis has shown that C.elegans contains a full set of proteins with high homology to the mammalian members of the PDI family (apart from PDIp). We will use RNA-mediated gene inactivation of specific PDI-related genes, combined with subsequent proteome analysis to characterise the in vivo functions of PDIs in C.elegans. Ultimately, this should lead to a deeper insight into the regulation and physiological function of protein disulphide isomerases in vivo

 

 

Interaction of peptidyl proly cis-trans isomerases with substrates

Domain architecture of SurA

The aim of this project is to characterize in more detail (in-vitro and in-vivo) the interaction between substrates and certain members of the protein disulphide isomerase (PDI) family, specifically PDI, ERp57 and PDIp, since these proteins show a comparable domain architecture.

These results will enable the prediction of substrate specificity and potential regulation of other members of the PDI family, e.g. ERp72 and P5. In collaboration with Dr. Lloyd W. Ruddock, Biocentre Oulu, Finland, mutants of PDI and PDIp are generated and the effect of these mutations on the structure, function and specificity is tested.

The aim of this project is to characterize in more detail (in-vitro and in-vivo) the interaction between substrates and certain members of the protein disulphide isomerase (PDI) family, specifically PDI, ERp57 and PDIp, since these proteins show a comparable domain architecture.

These results will enable the prediction of substrate specificity and potential regulation of other members of the PDI family, e.g. ERp72 and P5. In collaboration with Dr. Lloyd W. Ruddock, Biocentre Oulu, Finland, mutants of PDI and PDIp are generated and the effect of these mutations on the structure, function and specificity is tested.

More about specificity of folding catalysis

 

Acknowledgements:

Funding from: Wellcome Trust, BBSRC and Royal Society

 

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Enquiries: Phone: +44 (0)1227 823743

School of Biosciences, University of Kent, Canterbury, Kent, CT2 7NJ

Last Updated: 30/06/2016