Designing Peptide-Based Biosensors for the Diagnosis of Crystal Arthropathies

Date
2023-05-15
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Abstract
Peptides play a vital role in nature as they engage in many complex interactions which include forming proteins and binding with other biomolecules. The interactions between peptide and various biomolecules, such as proteins, carbohydrates, and enzymes, have been well-studied as they guide many processes in the human body. However, peptide interactions with solid surfaces are not well understood. This work explores the binding of peptides to the surfaces of monosodium urate (MSU) crystals. MSU crystals accumulate in the joints of patients with acute gout, one of several types of crystal arthropathy. Other arthritides, including pseudo-gout and osteoarthritis, present similar symptoms to gout, but are characterised by accumulation of calcium pyrophosphate and hydroxyapatite crystals respectively. Misdiagnosis between these diseases when using current methods of crystal analysis. This thesis aimed to produce a fluorescent, peptide-based biosensor with specific binding to MSU crystals for the purpose of future development of a more accurate and efficient method for diagnosing gout. This was accomplished by first analysing data provided by characterising the MSU surface, peptide binding interactions, and proposing optimal peptide sequence candidates through computational analysis. Methods were then developed to synthesise, fluorescently label, and purify the peptide candidates. Analytical methods, including RP-HPLC-UV, fluorescence spectrometry, and CD polarimetry, were employed to investigate the peptide’s binding affinities, fluorescent activity, and secondary structure. Finally, fluorescence microscopy images of the MSU-bound fluorescent peptides were analysed to compare relative binding of different peptide sequences to MSU crystals. Ultimately, this work was successful in identifying and synthesising fluorescent peptides that display strong, uniform binding to MSU crystals and enhance detection of the crystals via fluorescence microscopy. The findings of this thesis could be used in further studies to potentially develop an effective, peptide-based biosensor for gout.
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Keywords
Peptides, Medicinal, Sensor, Fluorescence, Diagnostic, Synthesis
Citation
Meyer, J. M. (2023). Designing peptide-based biosensors for the diagnosis of crystal arthropathies (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.