Prion proteins are small infectious particles that are formed by the miss-folding of the protein structure. It is believed the miss-folding of such proteins has been the cause of disease such as Bovine spongiform encephalopathy in cows and Creutzfeldt-Jakob disease in humans. The prion proteins that are known to mankind so far suggest that they affect the brain of the affected individual. “A study1 in the British Medical Journal reveals that 1 in 2,000 people in the United Kingdom might harbour the infectious prion protein that causes variant Creutzfeldt–Jakob disease (vCJD).”(Callaway, 2013). The study therefore shows that a high number of people are at risk and this is a cause for concern as the prion protein which is miss-folded prompts normal proteins present in the brain, to alter their structure so they also become miss folded. The miss folded structure is understood to be very stable and as levels of the protein build up within the infected tissue this results in destruction and eventually death of the cell. The prion protein, PrP is thought to be the cause of all mammalian prion diseases but the structure of the protein is yet to be discovered. The normal cellular form of the prion protein is PrPc, whereas the miss folded scrapie form is PrPSc. PrPc is constructed from 209 amino acids and one disulphide bond and are found on cell membranes. “Several topological forms exist; one cell surface form anchored via glycolipid and two transmembrane forms.”(Hedge et al, 1998). The miss folded form, PrPSc has more Beta sheets however the normal form PrPc has Alpha structure present. “Fourier-transform infrared (FTIR) spectroscopy demonstrated that PrPC has a high alpha-helix content (42%) and no beta-sheet (3%), findings that were c...
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...e N-terminal domain converting it to a helical structure”.(Muira et al, 1996). The binding of copper with the prion has many effects. A study on mice found those with the PrP had higher levels of copper uptake compared to the mice that didn’t have the PrP. Furthermore other research has found the binding of copper with the prion protein prevents unusual interactions with other proteins such as plasminogen. This evidence suggests the binding of copper with the PrP has a protective effect. Investigation has shown that if the copper uptake is disturb this can cause long term potentiation. “Imbalance in synaptic Cu causes disturbance in the activity of receptors such as GABA receptors and alters long term potentiation.”(Gabrielsson et al 1986; Vlachova et al, 1996). An experiment found that if cells were exposed to copper, this result in the increase of the uptake rate.
Guyer, Ruth Levy, Ph.D. “Prions: Puzzling Infectious Proteins” National Institutes of Health Office of Science. 28 July 2006 < science.education.nih.gov/nihHTML/ose/snapshots/multimedia/ritn/prions/prions1.html>.
...s to interfere with bonding to the receptors. The final possibility uses CNP, which downregulates the activation in MAP kinase pathways in the chondrocytes (4).
Mad Cow Disease, scientifically referred to as (BSE) Bovine Spongiform Encephalopathy, is a disease that affects those humans who eat the meat from infected cows. Mad Cow Disease is one of several fatal brain diseases called (TSE) Transmissible Spongiform Encephalopathy. (USDA) There was evidence of a new illness resembling the sheep disease scrapie. It was technically named BSE but quickly acquired the mad cow tag because of the way infected cattle behave. (CNN) In 1997, there was an award given to Stanley Prusiner, for concluding that a distorted protein called a prion was responsible for Mad Cow Disease, noted the long incubation period made it difficult to distinguish (Bryant). Another name for Mad Cow Disease is the new variant Cruetzfeldt-Jakob Disease (vCJD), similar to the Creutzfeldt-Jakob Disease, which is a deadly brain illness that strikes about one per million per year (USDA) due to genetic or unknown causes while the vCJD is contracted from eating infected cows (USDA). Both CJD and vCJD are so similarly named because of the similar effects from the illness.
Creutzfeldt-Jakob is known as a prion disease. Prion is a protein that occurs normally inside the brain, however
In sporadic CJD, the disease occurs even though the affected does not have any known risk factors that would cause an occurrence of the disease. This sudden occurring CJD is indisputably the most frequently diagnosed type of Creutzfeldt - Jakob disease. This statistically accounts for at least 85 percent of CJD cases. Due to that there are some fifty to sixty deaths per year due to sporadic CJD in the United States alone. Similar figures are seen in other countries such as Australia, Canada and the United Kingdom.
The origin of CWD has yet to be determined (Sigurdson & Aguzzi, 2007). The infection was first noted in 1967 at a captive mule deer research facility. In 1978 pathologists recognized the TSE type brain lesions, also that CWD presented as a prion disease by the neuronal perikaryonic vacuoles, the accumulation of aggregated prion protein and prion infectivity in the brain. In the late 1970s and early 1980s the infection w...
PrP can occur in two forms- a normal cellular prion protein known as PrPc and a pathogenic misfolded conformer known as PrPsc. The abnormal PrPsc differs from the normal prion protein PrPc in both secondary and tertiary structure. PrPsc is principally rich in Beta sheet contents but PrPc is principally rich in alpha helical contents. Due to this difference of between the isoforms, prions are extremely resistant to certain decontamination systems. The Two tables below outline both human and animal diseases (2).
Action potentials in neurons are facilitated by neurotransmitters released from the terminal button of the presynaptic neuron into the synaptic gap where the neurotransmitter binds with receptor sites on the postsynaptic neuron. Dopamine (DA) is released into the synaptic gap exciting the neighboring neuron, and is then reabsorbed into the neuron of origin through dopamine transporter...
Autopsies of affected cattle reveal holes in the brain tissue that give it a spongy, or spongiform, texture. Similar spongiform diseases have been recognized in humans (for example, Creutzfeldt-Jakob disease or CJD) for over a century and in sheep (scrapie) for over 200 years. The cause of BSE is unproven, although there is strong evidence that prions, which may be infective proteins, are the agent. Other hypotheses suggest that prions work with an as yet undetected virus to cause the infection.
The prion diseases that Chronic Wasting Disease is related to are Creutzfeldt-Jakobs disease found in humans, bovine spongiform encephalopathy (BSE) in cattle, and scrapies in sheep (3,4). These diseases are grouped together because they share certain characteristics such as long incubation periods, spongiform changes that are associated with neural loss, and cause failure to induce inflammatory responses (Chronic Wasting Disease Alliance).
Prions are pathogens, and cause infections, like viruses. Prions cause many neurodegenerative diseases, but are made up of harmless proteins found in mammals and birds. The proteins are not in their normal form though, and once they enter the human brain, can cause severe brain infections. One thing that makes them different from viruses, is the lack of nucleic acids, which means they have no genetic code. Once in the brain, they make normal proteins turn into abnormal ones, which then multiply, causing severe infection. Soon, holes appear in the brain that can only be treated by incineration. An example of a disease caused by a prion would be the Mad Cow Disease, or the human equivalent Creutzfeldt–Jakob disease. Prions are very dangerous. While some people can confuse prions and viruses, there are some ways to tell the difference.
Most of the aluminium in plasma is bound to the iron-transporting protein transferrin. Aluminium accumulates in areas of the brain with the highest concentration of transferrin receptors such as the cortex, hippocampus and amygdala; the same areas vulnerable to the development of Alzhiemer disease. The distribution of Aluminium in the brain reflects the neurones with the highest requirements for iron. The entry of aluminium into the brain mediated through transferrin.
Creutzfeldt-Jakob Disease is an uncommon, deteriorating, consistently fatal brain disorder that is caused by prions. The symptoms of CJD are similar of Alzheimer’s but progress much faster. There are three variations of CJD, sporadic, familial, and acquired. All variations affect the brain the same way and have the same result of death. CJD is an untreatable and incurable disease.
Epigenetics is the study of both heritable and non-heritable changes in gene translation, which do not stem from mutation. Epigenetic alterations to DNA may occur in several different ways; histone modification, DNA methylations, expression of microRNAs, and changes of the chromatin structure (Ntanasis-Stathopoulos et al). Depending on their presentation, they may be passed on to offspring. The exact mechanism of heritable epigenetic modification has not been discovered, but all of these alterations may have some impact on a wide range of disorders and have far reaching implications in the medical field. The study of epigenetics seeks to answer the age old question of whether nature or nurture is responsible for our phenotype, and it has arrived at the answer that in fact, both are. The discovery of epigenetic changes may lead us to cure many disorders, and even personality problems.
Proteins are considered to be the most versatile macromolecules in a living system. This is because they serve crucial functions in all biological processes. Proteins are linear polymers, and they are made up of monomer units that are called amino acids. The sequence of the amino acids linked together is referred to as the primary structure. A protein will spontaneously fold up into a 3D shape caused by the hydrogen bonding of amino acids near each other. This 3D structure is determined by the sequence of the amino acids. The 3D structure is referred to as the secondary structure. There is also a tertiary structure, which is formed by the long-range interactions of the amino acids. Protein function is directly dependent on this 3D structure.