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).
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Macromolecules are define as large molecules of structures found in living organisms. There are four types of macromolecules, which are proteins, carbohydrate, nucleic acid, and lipids also known as fats. Carbohydrates, proteins, and nucleic acids are made of monomers, which are structural units that eventually attached together to form polymers (Dooley 20). For instance, proteins are made of amino acids, which are monomers. In addition, it has a complex structure, which consist of four different levels, primary, secondary, tertiary, and quaternary. The first structure of protein is the primary structure, which is the sequence of amino acid, while in the secondary structure alpha and beta helices are formed. The structure, in which a protein becomes active, is in the tertiary structure, which is where polypeptide subunits fold. Meanwhile, only certain proteins have the quaternary structure, which is when, more than one polypeptide folds. Proteins are prominent macromolecules mainly because of their numerous functions. For instance, proteins are known for increasing the rate of reactions due to that enzymes are a type of protein. In addition, they are a form of defense mechanism such as they attack pathogens, which cause diseases. In other words, scientists study and gain more insight on certain illness and how to prevent them by using proteins. For example, in a recent study,
Fig 1: Applications of single molecule spectroscopy in solving scientific problems in Physics, Chemistry and Biology
Unlike microtubules, actin filaments are globular chains made of a single monomer, which is called globular actin (G-Actin). Actins is somehow similar to tubulin in which actin subunits have binding site for a nucleotide, but it is mainly Adenosine Triphosphate (ATP), not GTP as in tubulins. Polymerization of actin filaments is also similar to microtubules polymerization in which assembly of subunit in head-to-tail orientation to create polarity. Actin filaments consist of two parallel helical protofilaments, or F-actin. In contrast with microtubules, actin filaments are the thinnest among cytoskeletal filaments, with a diameter of 5-9 nm, that’s why they are also known as ‘microfilaments’. Localization of actin filaments
Protein have connection with amino acid to help in functions of: skin, muscle, hair and bones
Proteins are one of the four major macromolecules that carry out various biochemical reactions functions in living organisms. Some types of proteins include hormonal, transport, contractile, enzymatic proteins and more (OpenStax College). Hormonal proteins, like insulin, regulate blood glucose levels. Transport proteins, like hemoglobin, have a strong affinity to bind to oxygen due to iron, allowing oxygen to circulate throughout the body. Contractile proteins, like myosin, are small filaments that generate energy to move muscle tissues. Enzymatic proteins, like pepsin in the digestive system aid in breaking foods containing protein, which can be used for metabolic activities.
Spider silk is well known for its strength yet elastic nature, and for this reason scientists
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.
“Proteins are large, complex molecules that play many critical roles in the body” (Genetics Home Reference, 2014, p. xx-xx). “They do most of the work in cells and are required for the structure, function, and regulation of the body’s tissues and organs” (Genetics Home Reference, 2014, p. xx-xx). “Proteins are made up of hundreds or thousands of smaller units called amino acids, which are attached to one another in long chains” (Genetics Home Reference , 2014, p. xx-xx). “There are 20 different types of amino acids that can be combined to make a protein” (Genetics Home Reference, 2014, p. xx-xx). “The sequence of amino acids determines each protein’s unique 3-dimensional structure and its specific function” (Genetics Home Reference, 2014, p. xx-xx).
Macromolecules are large molecules that are made up of many smaller molecules and can be found in living things. They are formed through polymerization. Polymerization occurs when smaller molecules (monomers) join together to create larger molecules (polymers). Macromolecules are sorted by their chemical composition into the groups: carbohydrates, lipids, nucleic acids and proteins all of which are essential for living things to. The carbohydrates and lipids are needed for energy. But, carbohydrates are the main source of energy for living things, while, lipids mainly stores the energy. Proteins are used to build and maintain bones including muscle and
Protein. This places a crucial role as it helps maintain the body tissue, as well as helps repair damaged body tissue, and it assists in the growth of the human body. Proteins contain amino acids, which help assist the building blocks of the body. Energy is essential for the functioning of the body, and protein helps give the body energy.
Proteins are essential to cells. They are found in eukaryotic cells. They help cells maintain their shape. They are essential in humans’ immune systems and all over the body. Amino acids are what go into proteins. There are 20 different types of Amino acids. Nine of them are essential and eleven are non-essential. Peoples body mass is made up with 15% of proteins. Each protein has a certain “job.” Hydrogen bonds, Ionic bonds or covalent bonds are formed in a protein molecule.
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...
Proteins (macronutrient), which are found in animal products, nuts and beans, they help to build new cells, maintain tissue and synthesis new proteins essential for performing basic bodily functions. Proteins are in abundance in the human body and are present in the outer and inner membranes of all living cells (Dummies, 2018). Proteins are essential for building new cells, maintaining tissue and helping new proteins needed for basic bodily function (
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.
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).