Regulation of Biological Protein Activity - Essay Example

Regulation of Biological Protein ActivityProteins are dynamic structures whose function invariably depends on the interaction with other molecules. Many proteins function by the reversible binding with other molecules. The molecule that is bound by the protein is known as a ligand, which may also be another protein (Cooper, 2000). The transient interaction between proteins and ligands is crucial for the normal functioning of the cells. On the protein, the ligand binds to the binding site which is complementary to the ligand shape, size, charge, hydrophobic and hydrophilic character.

In addition, the interaction between the functional protein and the ligand is specific allowing it to discriminate other protein molecules. Regulation of this protein-ligand interaction is necessary for the regulation of the function of the cell (Cooper, 2000). This paper will discuss the various ways the cell regulates the functions of proteins.Proteins are essential for the normal functioning of the cell. These include the cell wall, nucleus, enzymes and other essential components are made up of proteins.

The biological function of proteins is regulated at the molecular interaction of the protein with the ligand. This includes causing conformational changes on the protein or through specific interactions with one or more additional ligands (Petsko, 2003). Enzymes are proteins that bind to other proteins causing chemical transformation in the proteins. Regulation of the function of proteins involves the alteration of the chemical interaction between the enzyme and the substrate.The regulation of proteins plays a significant role in determining the functioning of the cell.

Proteins are regulated at the gene expression level as well as the function level. Regulation at the gene expression level determines the quantity and quality of proteins that are synthesized by the cell. This involves the activity of transcription and translation factors. Transcription factors are involved in regulating the flow of information from DNA to the mRNA while the translation factors regulate the translation of mRNA to functional proteins (Merrick, 1992).Majority of the proteins are regulated by causing a conformational change that alters the functioning of the cell.

Allosteric regulation of proteins involves the binding of regulatory proteins at a site other than the protein active site. The binding of the allosteric protein then causes a conformational change in the proteins that may either active or inhibit the function of the protein. An example is the binding of oxygen on haemoglobin (Merrick, 1992). The binding of the first molecule of oxygen to the haemoglobin protein causes conformational changes on the haemoglobin protein thus enabling the binding of other oxygen molecules.

Protein function may also be regulated by the formation of either covalent or noncovalent bond association with other proteins. Noncovalent bond associations are reversible thus allowing the protein to regain function after dissociation. Protein phosphorylation is a reversible process which is essential in the regulation of proteins (Eissa, 2012). Protein phosphorylation is facilitated by the protein kinase enzymes that transfer the phosphate group to the hydroxyl group of proteins. This process is reversed by the catalysis of the phosphorylated amino acid by the protein phosphatases.

The combination of the kinase and phosphatase facilitates the reversible phosphorylation of the protein function. They are applied in signal transduction pathways where proteins are used.Proteins are composed of multiple subunits, which are made of an independent polypeptide chain. The interactions between the polypeptide chains are essential in the regulation of proteins. These interactions between the polypeptide chains are specific to proteins. Regulation at the translation and transcription regulation proteins is dependent on the protein to protein interaction.

This factors act as either inhibitors or activators by altering the interaction between the proteins. The biological function of proteins can be regulated by altering the environment at which the proteins function. Proteins function at a specific Ph environment. Alteration of the Ph will alter the normal functioning of the proteins.ReferencesCooper, G. (2000) The cell: A molecular approach, NY: Elsevier.Eissa, S. (2012) Protein Phosphorylation and Dephosphorylation: A mechanism of acute and reversible regulation of protein function, NJ: Prentice Hall.

Merrick, C. (1992) “Mechanism and regulation of eukaryotic protein synthesis”, Microbiology molecular biology, Vol. 56, no. 2: 291-315.Petsko, G. (2003) Protein Structure and function, London: Routledge.