DYNAMIC OF BIOMOLECULES AND CELLS 2014
Unfolding the elastomeric protein titin using atomic force microscopy
Why atomic force microscopy is most suited to this task
An essay on the role atomic force microscopy plays in the unfolding of titin and why atomic force microscopy is suited to such experiments
Proteins are a group of molecules, present in the human body (and other living organisms), that have varied functions. They are made up of chains of smaller molecules called amino acids. The amino acids are arranged in long strings, these strings are then folded into shapes to create a functional component.
Proteins have lots of different functions, such as bio-regulation (in the case of hormones). There exist transport proteins that for example move minerals through the body, structural proteins make up the skin, bones and some proteins are catalytic (enzymes).
This essay focusses on an elastomeric protein. An elastomer is an elastic polymer; elastomeric proteins are multi-unit proteins that display elasticity.
Elasticity is ability of a solid material to return to the original form after deformation. The physical origin for elasticity varies per material. In the case of rubber and other elastic polymers, the elasticity arises from the stretching of the polymer chain (when force is applied to it) that the elastic polymer is made of.
To study the elasticity of proteins, a tool has to be used that can measure the force required to make a certain extension of the polymer. One such tool is the atomic force microscope (AFM).
An AFM uses a sharp tip on a cantilever that will deflect when it is brought in close proximity to a surface. The deflection of the cantilever can be measured and the topography of the sample...
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...i, Z. & Kellermayer, M. Individual globular domains and domain unfolding visualized in overstretched titin molecules with atomic force microscopy. PLoS One 9, e85847 (2014).
15. Puchner, E. M. et al. Mechanoenzymatics of titin kinase. Proc. Natl. Acad. Sci. U. S. A. 105, 13385–90 (2008).
16. Kellermayer, M. S. & Granzier, H. L. Elastic properties of single titin molecules made visible through fluorescent F-actin binding. Biochem. Biophys. Res. Commun. 221, 491–7 (1996).
17. Neuman, K. C. & Nagy, A. Single-molecule force spectroscopy: optical tweezers, magnetic tweezers and atomic force microscopy. Nat. Methods 5, 491–505 (2008).
18. Jannasch, A., Demirörs, A. F., van Oostrum, P. D. J., van Blaaderen, A. & Schäffer, E. Nanonewton optical force trap employing anti-reflection coated, high-refractive-index titania microspheres. Nat. Photonics 6, 469–473 (2012).
Thermal methods of analysis have been in use for quite a long time. Their application in the analysis of pharmaceutical materials has made it possible for pharmacists and researchers to understand their contents and characteristics. However, thermal methods have several disadvantages that have led researchers to opt for nano-thermal methods of analysis. Nano-thermal analysis methods use special resolution imaging potential that is enhanced by the availability of atomic force microscopy and thermal analysis methods.
The small size ranging from 0.1 to 10 micrometres of nanobots make it difficult to be constructed. The process of working atom by atom and molecule by molecule is monotonous work and the miniaturization of synthetic mechanisms to a nanoscale will only be achievable with the advancement of research in metallurgy.
Scibd. N.p. Web. 17 Mar 2014. Beller, Michele.
Lovgren, Stefan. Can Art Make Nanotechnology Easier t Understand? 23 December 2003. Web. 3 May 2014. .
Proteins are one of the main building blocks of the body. They are required for the structure, function, and regulation of the body’s tissues and organs. Even smaller units create proteins; these are called amino acids. There are twenty different types of amino acids, and all twenty are configured in many different chains and sequences, producing differing protein structures and functions. An enzyme is a specialized protein that participates in chemical reactions where they serve as catalysts to speed up said reactions, or reduce the energy of activation, noted as Ea (Mader & Windelspecht).
There are nine amino acids that are considered “essential” for health, which we must obtain from our diets since our bodies cannot make them on their own. Some of the roles that amino acids/proteins have include helping to form and maintain muscle mass, providing energy for our cells and brain, helping store away energy for later use in fat stores, making your heart beat, and helping build the foundation of vital organs, including your heart, lungs and even your DNA, and supporting growth/development. Because of its ties to lean muscle mass and satiety in terms of controlling your appetite, protein is especially important as you age.
Polymer chains are long, individual chains, although they behave as if they are attached to each other. The individual chains are actually held together by ‘Electrostatic Forces’ between molecules, also known as ‘Hydrogen Bonds’. Scientists discovered this, by using a special type of X-ray microscopy called ‘XANES’. This was able to reveal the orientation of molecules in materials. It has also been discovered that the components of Kevlar fiber, have a radial orientation that is in a crystal. The crystal-like regularity is the largest contributing factor in the strength of Kevlar fiber.
Protein have connection with amino acid to help in functions of: skin, muscle, hair and bones
When eaten, protein is broken down into amino acids. Proteins and amino acids are used for almost every metabolic process in the body, and are the building blocks for every tissue in your body.
The cytoskeleton is made up of three different types of filaments, actin filaments, intermediate filaments and microtubules. Actin filaments are the thinnest, they are also known as microfilaments. They create a band under the plasma membrane, this gives strength to the cell and links transmembrane proteins such as cell surface receptors to cytoplasmic proteins. Intermediate filaments include keratins, lamins, neurofilaments and vimentins. Keratins form hooves, horns and hair and are found in epithelial cells. Lamins form a type of mesh that ‘stabilizes the inner membrane of the nuclear envelope’ (Biology Pages). Neurofilaments bring strength to the axons of neurons and vimentins provide mechanical support to cells – particularly muscles. The cytoskeleton is also involved in cell
Keratin, this protein gives mechanical support to the body. It makes the outermost layer of human skin, hair, and nails, and the scales. hooves, and feathers of animals. It twists into a regularly repeating coil is called an alpha helix. Serving to protect the body against the environment, keratin is completely insoluble in water.
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.
There are four main levels of a protein, which make up its native conformation. The first level, primary structure, is just the basic order of all the amino acids. The amino acids are held together by strong peptide bonds. The next level of protein organization is the secondary structure. This is where the primary structure is repeated folded so that it takes up less space. There are two types of folding, the first of which is beta-pleated sheets, where the primary structure would resemble continuous spikes forming a horizontal strip. The seco...
"Within a single subunit [polypeptide chain], contiguous portions of the polypeptide chain frequently fold into compact, local semi-independent units called domains." - Richardson, 1981
Law of elasticity is known as Hooke’s law, showing the relationship between the forces applied to a spring and its elasticity, which states that relationship between small deformation of the object and the displacement or size are directly proportional to loading and the deforming force. According to Hooke’s law, elastic behaviour of solids could explain by the fact that in component ions, molecules, or atoms from normal positions, which is small deformation, are also proportional to the force that causes the displacement. The deforming force might be applied to a solid by squeezing, compressing, stretching twisting, or bending. Accordingly, spring will return to its primary size and shape upon discharge of the load (Tega, 2010).