Tuesday, February 1, 2011


*.proteins are large, complex molecules that carry put the task of life
*they direct our bodies activities, organize our thoughts and defense us against infection, keeping us healthy
*but in their mutant forms and as coats on disease causing microbes, proteins can help make us in and threaten our health
*each protein is initially found as a string of a amino acid whose identity and order are dictated by a genes instructions carried by m rna also called for this strings to be folded into a three dimensional molecule and has intricate shape, ranging from a saucer to a dumbbell to a cork screw
*the amino acid composition and sequence as well as the molecular weight, of a protein produced by a certain type of bacteria different from those of the protein forming the coat of the particular virus
*such a coat enables this molecular terrorist to break through the protective membrane of a cell and command it to produce more virus
*each types of microbe produce unique proteins , providing a characteristic protein , signature and allowing and identification of micro organism thus, if the signature protein in the anthrax spores and botulism toxins could be accurately detected, it would be possible to provide an early warning about the proximity of biological warfare weapons
*the ability to identify protein is also important because it allows researcher to determine whether an organism has genetic disease
*a genetic disease it often caused by a mutant proteins , which has a composition slightly different from that of the normal proteins it replaces
*one of the most powerful tools for detecting and identifying proteins in mass spectrometry, a technique has been improved and use for a variety of research products
*a mass spectrometer is an ideal for identifying amino acids
*the building block of proteins and determine the order in which they are arranged the mass differences or distance in atomic mass units between the peaks along the spectrum, allows each amino acids
Eg: alanine, arsanine,glycine to be identified

*a plot used by biologist to display the pairs of angles ( ø, Ψ ) that govern the twist in the chain of amino acids forming a protein
*each pair of angles is represented by a point in a square whose limits , on each axis, correspond to-180deg , 180deg


*in cases when the proteins x ray structure was not properly refined and even for bad or wrong homology models,we may find torsion angle in dis allowed region of the ramachandran plot
* usually this deviation indicates a problem with the structure ,suggesting that the ramachandran plot may be used in accessing the quality of experimental structures of structures built using homology model
*the ramachandrana plot exposure is designed to make it easy to examine the conformation of a polypeptide through the interactive ramachandrana plot r and x angle tools

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