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Updated: Mar 7, 2026
Protein Misfolding Cyclic Amplification of Prions
Published on: November 7, 2012
Ultra-efficient Amplification of Abnormal Prion Protein by Modified Protein Misfolding Cyclic Amplification with
Jeong-Ho Park1,2, Yeong-Gon Choi2, Seok-Joo Park2
1Department of Microbiology, College of Medicine, Hallym University, Chuncheon, Gangwon-do, 24252, Republic of Korea.
Abstract:
Prion diseases are clinically diagnosed and confirmed upon post-mortem histopathological examination of brain tissue. The only reliable molecular marker for prion diseases is abnormal prion protein (PrPSc), a pathologically conformed prion protein that primarily accumulates in the central nervous system and to a lesser extent in lymphoreticular tissues. However, the use of PrPSc as a marker for preclinical diagnoses is limited because the concentration of PrPSc in easily accessible body fluids is extremely low. Hence, one of the most promising approaches would be the development of an efficient in vitro amplification method for PrPSc. Indeed, protein misfolding cyclic amplification (PMCA) has become an important diagnostic tool for prion diseases. Here, we first describe a new superior PMCA device that employs electricity (referred to as ePMCA) to amplify PrPSc. The ePMCA device markedly improved the detection limit for PrPSc by amplifying trace amounts of pathogenic prion protein by applying electricity to improve PMCA. To increase the cavitation of sonication, a glass sample tube was used, and the upper side of the horn was shaped such that it had a curved cross-section. The ePMCA device enabled PrPSc to be amplified even from a sample seeded with 10-28-fold diluted 263K scrapie-infected brain homogenates with recombinant hamster prion protein (rHaPrP). In addition, the efficiency of prion amplification was best when 50 mM HEPES and 1% Triton X-100 were used as a PMCA conversion buffer in the various conditions that we applied. These results indicate that ePMCA would be very valuable for the rapid and specific diagnosis of human prion diseases and, thus, may provide a practically improved method for antemortem diagnoses using the body fluids of patients and animals with prion disease.
Insights
A new electrical protein misfolding cyclic amplification (ePMCA) device significantly enhances prion detection in body fluids. This breakthrough offers a promising tool for earlier diagnosis of prion diseases, improving patient outcomes.
Area of Science:
- Neuroscience
- Biochemistry
- Medical Diagnostics
Background:
- Prion diseases are diagnosed post-mortem via histopathology.
- Abnormal prion protein (PrPSc) is the key marker but present at low levels in body fluids, limiting preclinical diagnosis.
- Protein misfolding cyclic amplification (PMCA) is an established in vitro diagnostic tool for prion diseases.
Purpose of the Study:
- To develop a superior PMCA device (ePMCA) for enhanced amplification of PrPSc.
- To improve the detection limit of PrPSc in accessible body fluids for earlier prion disease diagnosis.
Main Methods:
- Development of an electrical PMCA (ePMCA) device utilizing electricity to amplify PrPSc.
- Optimization of ePMCA by employing a glass sample tube and a specially shaped horn to increase sonication cavitation.
- Testing ePMCA with serially diluted 263K scrapie-infected brain homogenates and recombinant hamster prion protein (rHaPrP).
Main Results:
- The ePMCA device markedly improved the detection limit for PrPSc.
- ePMCA successfully amplified PrPSc from samples diluted up to 10-28-fold.
- Optimal amplification efficiency was achieved using 50 mM HEPES and 1% Triton X-100 as the conversion buffer.
Conclusions:
- The ePMCA device represents a significant advancement in amplifying trace amounts of pathogenic prion protein.
- ePMCA holds substantial potential for rapid, specific, and improved antemortem diagnosis of human prion diseases.
- This technology could enable earlier diagnosis through analysis of patient and animal body fluids.
