What is topology in protein structure?
The topology of a protein structure is a highly simplified description of its fold including only the sequence of secondary structure elements, and their relative spatial positions and approximate orientations. This information can be embodied in a two-dimensional diagram of protein topology, called a TOPS cartoon.
How is protein topology determined?
The topology of a membrane protein is, in most cases, determined during the initial insertion of the polypeptide chain into the membrane. With few exceptions, the insertion is mediated by a translocon — a molecular gate-keeper that allows nascent polypeptide chains to pass across or integrate into lipid membranes.
What is Biochem topology?
In biochemistry, membrane topology is used as a method or analysis to determine and predict the orientation of transmembrane protein in the lipid bilayer. In ecology, topology is the study of patterns of interconnections in a network system, and specifically called ecological topology.
What protein is a structural protein?
Keratin is the main structural protein that forms the hair, wool, feathers, nails, and horns of many types of animals. This protein has a high content of cysteine (7–20% of the total amino acid residues), which is known to form intramolecular and intermolecular disulfide bonds [39, 40].
What is topology diagram?
A network topology diagram is a visual representation of a network’s devices, connections, and paths, allowing you to picture how devices are interconnected and how they communicate with one another. The most common topologies are: Bus topology. All devices are connected by one central cable with two endpoints.
How does protein fold?
Folded proteins are held together by various molecular interactions. During translation, each protein is synthesized as a linear chain of amino acids or a random coil which does not have a stable 3D structure. The amino acids in the chain eventually interact with each other to form a well-defined, folded protein.
What is the positive inside rule?
Inner membrane proteins have long been known to follow the “positive-inside rule”, where cytoplasmic loops tend to have a greater number of cationic residues than periplasmic or extracellular loops. Addition or removal of positive charge can bias the orientation of the inserted protein.
What do lipid anchored proteins do?
Lipid-anchored proteins (also known as lipid-linked proteins) are proteins located on the surface of the cell membrane that are covalently attached to lipids embedded within the cell membrane. Thus, the lipid serves to anchor the protein to the cell membrane. They are a type of proteolipids.
What is DNA topology?
The topology of DNA, which is defined by how the two complementary single strands are intertwined, has been an important consideration since the double helical structure of DNA was first proposed by Watson and Crick in 1953 (1).
What is topology in polymers?
Topological polymers may refer to a polymeric molecule that possesses unique spatial features, such as linear, branched, or cyclic architectures. Topological structures, along with the chemical composition, determine the macroscopic physical properties of polymeric materials.