Multiple folding pathways for heterologously expressed human prion protein.

Abstract

Human PrP (residues 91-231) expressed in Escherichia coli can adopt several conformations in solution depending on pH, redox conditions and denaturant concentration. Oxidised PrP at neutral pH, with the disulphide bond intact, is a soluble monomer which contains 47% alpha-helix and corresponds to PrPC. Denaturation studies show that this structure has a relatively small, solvent-excluded core and unfolds to an unstructured state in a single, co-operative transition with a DeltaG for folding of -5.6 kcal mol-1. The unfolding behaviour is sensitive to pH and at 4.0 or below the molecule unfolds via a stable folding intermediate. This equilibrium intermediate has a reduced helical content and aggregates over several hours. When the disulphide bond is reduced the protein adopts different conformations depending upon pH. At neutral pH or above, the reduced protein has an alpha-helical fold, which is identical to that observed for the oxidised protein. At pH 4 or below, the conformation rearranges to a fold that contains a high proportion of beta-sheet structure. In the reduced state the alpha- and beta-forms are slowly inter-convertible whereas when oxidised the protein can only adopt an alpha-conformation in free solution. The data we present here shows that the human prion protein can exist in multiple conformations some of which are known to be capable of forming fibrils. The precise conformation that human PrP adopts and the pathways for unfolding are dependent upon solvent conditions. The conditions we examined are within the range that a protein may encounter in sub-cellular compartments and may have implications for the mechanism of conversion of PrPC to PrPSc in vivo. Since the conversion of PrPC to PrPSc is accompanied by a switch in secondary structure from alpha to beta, this system provides a useful model for studying major structural rearrangements in the prion protein. Study holds ProTherm entries: 15094, 15095, 15096, 15097, 15098 Extra Details: Folding to Unfolding prion; protein folding; thermodynamics; circular dichroism; recombinant expression; NMR

Submission Details

ID: NfUgQ3sN3

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:45 p.m.

Version: 1

Publication Details
Jackson GS;Hill AF;Joseph C;Hosszu L;Power A;Waltho JP;Clarke AR;Collinge J,Biochim. Biophys. Acta (1999) Multiple folding pathways for heterologously expressed human prion protein. PMID:10209273
Additional Information

Study Summary

Number of data points 5
Proteins Major prion protein ; Major prion protein
Unique complexes 1
Assays/Quantities/Protocols Experimental Assay: Tm prot_conc:25 micro M ; Experimental Assay: Tm prot_conc:12.5 micro M ; Experimental Assay: dG_H2O pH:4.0 ; Experimental Assay: dG_H2O pH:8.0
Libraries Mutations for sequence GSKKRPKPGGWNTGGSRYPGQGSPGGNRYPPQGGGGWGQPHGGGWGQPHGGGWGQPHGGGWGQPHGGGWGQGGGTHSQWNKPSKPKTNMKHMAGAAAAGAVVGGLGGYMLGSAMSRPIIHFGSDYEDRYYRENMHRYPNQVYYRPMDEYSNQNNFVHDCVNITIKQHTVTTTTKGENFTETDVKMMERVVEQMCITQYERESQAYYQRGS

Structure view and single mutant data analysis

Study data

No weblogo for data of varying length.
Colors: D E R H K S T N Q A V I L M F Y W C G P
 

Data Distribution

Studies with similar sequences (approximate matches)

Correlation with other assays (exact sequence matches)


Relevant UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
100.0 Major prion protein P04156 PRIO_HUMAN
99.6 Major prion protein P40252 PRIO_GORGO
99.2 Major prion protein P61766 PRIO_HYLLA
99.2 Major prion protein P61768 PRIO_PANTR
99.2 Major prion protein P61767 PRIO_SYMSY
98.1 Major prion protein P40256 PRIO_PONPY
97.2 Major prion protein P40251 PRIO_COLGU
96.3 Major prion protein P61761 PRIO_CERMO
96.3 Major prion protein P61762 PRIO_CERNE
95.9 Major prion protein Q95174 PRIO_ERYPA
96.4 Major prion protein P67993 PRIO_MACAR
96.4 Major prion protein P67992 PRIO_MACFA
96.4 Major prion protein P67994 PRIO_MACFU
96.4 Major prion protein P67997 PRIO_MACMU
96.4 Major prion protein P67995 PRIO_MACNE
96.4 Major prion protein P67996 PRIO_PAPHA
95.9 Major prion protein P40248 PRIO_PLEMO
95.9 Major prion protein P40255 PRIO_MANSP
95.9 Major prion protein Q95176 PRIO_CERAT
92.9 Major prion protein P67989 PRIO_CERDI
92.9 Major prion protein P67988 PRIO_CHLAE
93.1 Major prion protein P67990 PRIO_LOPAT
93.1 Major prion protein P67991 PRIO_MACSY
95.4 Major prion protein P40245 PRIO_AOTTR
91.3 Major prion protein Q95270 PRIO_THEGE
96.6 Major prion protein P40257 PRIO_TRAFR
95.3 Major prion protein P40247 PRIO_CALJA
95.3 Major prion protein P51446 PRIO_ATEPA
93.6 Major prion protein Q9Z0T3 PRIO_SIGHI
90.9 Major prion protein Q95M08 PRIO_BUDTA
93.4 Major prion protein P40246 PRIO_ATEGE
90.4 Major prion protein P52113 PRIO_CAPHI
90.4 Major prion protein Q7JIH3 PRIO_OVICA
90.4 Major prion protein Q7JIY2 PRIO_OVIMO
90.4 Major prion protein Q7JK02 PRIO_OVIMU
90.4 Major prion protein Q5XVM4 PRIO_RUPRU
90.4 Major prion protein P23907 PRIO_SHEEP
92.2 Major prion protein P13852 PRIO_RAT
92.2 Major prion protein Q60506 PRIO_CRIGR
92.3 Major prion protein P40258 PRIO_SAISC
92.9 Major prion protein P40249 PRIO_SAPAP
91.7 Major prion protein P04273 PRIO_MESAU
93.1 Major prion protein P04925 PRIO_MOUSE