RESUMEN
Prion diseases are progressive degenerative disorders of the central nervous system. The transmissibility and fatal nature of these diseases necessitate their rapid and accurate diagnosis. The hallmark of these diseases is the accumulation of PrPSc, a protease-resistant form of a host-coded glycoprotein. We have been evaluating the use of multi-spectral ultraviolet fluorescent spectroscopy as a means of detecting and distinguishing between different forms of PrPSc. Spectroscopic measurements of fluorescence from untreated and proteinase K (PK)-treated PrPSc, purified from 263K scrapie strain-infected hamster brains and ME7 scrapie strain-infected mouse brains, were performed. Spectra of untreated and PK-treated PrPSc samples for 263K and ME7 appeared qualitatively different. The identification and discrimination of PrPSc were possible based on these spectral signatures, calculations of their fluorescence cross sections, and determination of the orthogonal differences. This technique has the potential not only for the sensitive, specific, and direct detection of PrPSc, but also for the ability to distinguish between different forms of the prion protein.
Asunto(s)
Proteínas PrPSc/análisis , Espectrometría de Fluorescencia/métodos , Espectrofotometría Ultravioleta/métodos , Animales , Encéfalo/metabolismo , Cricetinae , Endopeptidasa K , Estudios de Evaluación como Asunto , Ratones , Proteínas PrPSc/aislamiento & purificación , Scrapie/diagnóstico , Scrapie/metabolismo , Sensibilidad y Especificidad , Especificidad de la Especie , Espectrometría de Fluorescencia/estadística & datos numéricos , Espectrofotometría Ultravioleta/estadística & datos numéricosRESUMEN
Recent interest in the detection and analysis of biological samples by spectroscopic methods has led to questions concerning the degree of distinguishability and biological variability of the UV fluorescent spectra from such complex samples. We show that the degree of distinguishability of such spectra is readily determined numerically. As a practical example of this technique, we show its application to the analysis of UV fluorescence spectra taken of E. coli, S. aureus, and S. typhimurium. The use of this analysis to determine the degree of biological variability and also to verify that measurements are being made in a linear regime in which analytic methods such as multivariate analysis are valid is discussed.
