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quote:Originally posted by vj_tuI just doubt how scientists determine the amino acid sequence of a protein of interest.In other words,how they know which amino acid is which?Then they can construct the sequence of that protein.
quote:Originally posted by DoctorBeaverI'm taking part in the Stanford university "Folding At Home" project. I don't really know what it's all about even though I posted about it here and got a few infomative replies.
quote:Protein folding is the process by which a protein structure assumes its functional shape or conformation. All protein molecules are heterogeneous unbranched chains of amino acids. By coiling and folding into a specific three-dimensional shape they are able to perform their biological function.
quote:Preconditions for correct foldingIn certain solutions and under some conditions proteins will not fold at all. Temperatures above or below the range that cells tend to live in will cause proteins to unfold or "denature" (this is why boiling makes the white of an egg opaque). High concentrations of solutes and extremes of pH can do the same. A fully denatured protein lacks both tertiary and secondary structure, and exists as a so-called random coil. Cells sometimes protect their proteins against the denaturing influence of heat with enzymes known as chaperones or heat shock proteins, which assist other proteins both in folding and in remaining folded. Some proteins never fold in cells at all except with the assistance of chaperone molecules, that isolate individual proteins so that their folding is not interrupted by interactions with other proteins. DNA conformation is maintained by another set of enzymes: the topoisomerases.Incorrect protein folding and neurodegenerative diseaseIncorrectly folded proteins are responsible for prion related illness such as Creutzfeldt-Jakob disease and Bovine spongiform encephalopathy (mad cow disease), and amyloid related illnesses such as Alzheimer's Disease. These diseases are associated with the aggregation of misfolded proteins into insoluble plaques; it is not known whether the plaques are the cause or merely a symptom of illness.
quote:Originally posted by DoctorBeaverWhat I do know about protein folding, however, is that Jehovah's Witnesses use it as an indication that we were created by God. They claim the immense complexity of it could not have been arrived at by random chance.