Protein Purification Protocol of the Glycogen Phosphorylase, Muscle Form (Human) – Term Paper Example

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The paper "Protein Purification Protocol of the Glycogen Phosphorylase, Muscle Form (Human)" is a good example of a term paper on chemistry.   Glycogen is one of the most abundant proteins in skeletal muscles consisting of about 4% in total. It is important for the utilization of glycogen reserves in the body muscles. Glycogen is a large highly branched polymer of glucose molecules. Most are joined by alpha 1, 4 to make straight chains, and alpha 1, 6 linkages occur every 8 to 12 glucose residues, to make branch points. There are two types of linkage found between the glucose molecules.

However, excess Glycogen phosphorylase is usually made of a cofactor pyridoxal phosphate strongly bound to it; this can be easily utilized to measure its degradation. The main sore of glycogen in the human body is found in skeletal muscles and the liver, where they serve as a fuel reserve for the synthesis of energy known as Adenosine Triphosphate (ATP) during the contraction process of muscles as well as in the liver. Basically glycogen is used to maintain the blood glucose level at equilibrium especially during the early stages of fasting as stated by Pergamon (1990). The Function or Role of Glycogen Phosphorylase in Human Beings Excess dietary of glucose is usually stored as glycogen in the body muscles.

Glucose can be rapidly ad easily mobilized from glycogen when the need arises; for instance, between meals or during exercise. A constant sufficient supply is very crucial for life because it is the main fuel of the brain and the only source of energy that can be used by cells that lack mitochondria or by the frequently contracting skeletal muscles in the process of anaerobic glycolysis.

Glycogen is therefore an excellent short-term storage material that can provide energy whenever required with an immediate effect. However, glycogen phosphorylase cleaves the alpha 1,4 bonds between glycosyl residues at the non-reducing ends of the glycogen chains thus producing glucose 1-phosphate. The protein requires pyridoxal phosphate as a coenzyme to activate the reaction as proposed by Storey (2004). Glycogen is used as an energy reserve. In the brain, it protects against hyp[oglycemia, since this organ functions constantly, while dietary intake of carbohydrates is intermittent.

For muscles, glycogen provides a more immediate and, and a more abundant source of glucose-phosphate than does blood sugar. It thereby provides the precursors for ATP production that enable more rapid and more extensive muscle action fro limited periods of required activity. It is therefore essential that cleavage of such stored glycogen molecules not occur steadily since this would deplete the glycogen or best lead to a futile cycle as glycogen consumption balanced the synthesis of new glycogen as proposed by (Newshome and Leech, 2009). However, muscle store glycogen, but it is not able to convert the Glc-1-P produced to free glucose, and uses the stored glycogen exclusively in the muscles for muscle action.

When the muscle is resting, it can obtain adequate energy from the use of fatty acids, and glycogen consumption is reserved for active work. Under conditions of active work, the muscle phosphorylase is then mainly activated by phosphorylation, in response to a hormone signal, and is also activated by AMP binding at the A site. Glucose itself remains the most effective inhibitor.

References

American Chemical Society (2008). Biochemistry, Volume 47, Issues 26-28. New York: American Chemical Society, print.

Colfen, H. (1999). Analytical ultracentrifugation V, Volume 5. New York: Springer, print.

Cutler P. (2004). Protein purification protocols. New Jersey: Humana Press, print

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Nelson J. (2008). Structure and function in cell signaling. London, UK: John Wiley & Sons

Newshome E., & Leech A. (2009). Functional Biochemistry in Health and Disease. Oxford: John Wiley and Sons

Pergamon (1990). Comparative biochemistry and physiology: Comparative biochemistry, Volume 95, Part 2. New York: Pergamon Press, 1990

Roe S. (2001). Protein purification applications: a practical approach. Oxford: oxford university press.

Storey B. K. (2004). Functional metabolism: regulation and adaptation. New Jersey: Wiley-IEEE, print.

Traut, T. (2007). Allosteric regulatory enzymes. Texas: Springer, print.

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