Abstract
The infectious protein or prion (PrPSC) is a transmissible and replicable polypeptide, which arises from an abnormal folding of the PrP protein, by unknown mechanisms and without changes in the primary sequence of its amino acids. Its new spatial disposition arises from the substitution of its alpha helices by beta bands, which increase its structural stability, avoiding its complete proteolysis, resulting in a residual accumulation of prions. These prions induce the misfolding of normal PrP protein, generating their exponential increase, leading to a disturbance of neuronal homeostasis which results in the development of the fatal spongiform encephalopathy of the Creutzfeldt-Jakob disease (CJD). This is the most prevalent human prion disease, and 90% of cases are sporadic, suggesting the endogenous genesis of prions. There are different types of prions, identified based on the genetic variance of codon 129 amino acids of the prion protein. Meteonin (M) and Valine (V)), associated with the result of their enzymatic proteolysis, define prions type 1 (21 kDa) and type 2 (19 kDa). The Classical form of CJD produced by MM1 prion occurs in 70% of the cases. The Cerebellar form originated by the VV2 prion occurs in 15% of cases, the form with Kuru plates, associated with the prion MV2 occurs in 5%, and the Vacuolar, related to the MM2 prion occurs in 4%. CJD is always characterized by behavioral, motor, cognitive, and vision alterations and by findings in magnetic resonance imaging, electroencephalogram and cerebrospinal fluid that define each clinical and neuropathological form.
Highlights
Recibido el 26 de agosto de 2018, aceptado el 8 de julio de Correspondencia a: Luis Cartier Rovirosa Av
The infectious protein or prion (PrPSC) is a transmissible and replicable polypeptide, which arises from an abnormal folding of the PrP protein, by unknown mechanisms and without changes in the primary sequence of its amino acids
Its new spatial disposition arises from the substitution of its alpha helices by beta bands, which increase its structural stability, avoiding its complete proteolysis, resulting in a residual accumulation of prions
Summary
Recibido el 26 de agosto de 2018, aceptado el 8 de julio de Correspondencia a: Luis Cartier Rovirosa Av. La historia de la Enfermedad de Creutzfeldt-Jakob (ECJ) se inicia en 1920 cuando Hans-Gerhard Creutzfeldt describió una paciente de mediana edad, que desarrolló deterioro cognitivo-motor de evolución subaguda, cuyo estudio neuropatológico mostró alteraciones degenerativas del SNC. En una serie de enfermos de comienzo cerebeloso, comunicada por Cooper y cols., el clásico VV del codón 129 se observó sólo en la mitad de los casos[24].
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have