An antibody (Ab), also known as an immunoglobulin (Ig), is a large, Y-shaped protein produced mainly by plasma cells that is used by the immune system to neutralize pathogens such as pathogenic bacteria and viruses. The antibody recognizes a unique molecule of the pathogen, called an antigen, via the fragment antigen-binding (Fab) variable region. Each tip of the "Y" of an antibody contains a paratope (analogous to a lock) that is specific for one particular epitope (similarly, analogous to a key) on an antigen, allowing these two structures to bind together with precision.
In cell biology, mitosis is a part of the cell cycle when replicated chromosomes are separated into two new nuclei. Cell division gives rise to genetically identical cells in which the number of chromosomes is maintained. In general, mitosis (division of the nucleus) is preceded by the S stage of interphase (during which the DNA is replicated) and is often accompanied or followed by cytokinesis, which divides the cytoplasm, organelles and cell membrane into two new cells containing roughly equal shares of these cellular components.
globularglobular proteinsalbumin globule
Globular proteins or spheroproteins are spherical ("globe-like") proteins and are one of the common protein types (the others being fibrous, disordered and membrane proteins). Globular proteins are somewhat water-soluble (forming colloids in water), unlike the fibrous or membrane proteins. There are multiple fold classes of globular proteins, since there are many different architectures that can fold into a roughly spherical shape.
Biomolecular structure is the intricate folded, three-dimensional shape that is formed by a molecule of protein, DNA, or RNA, and that is important to its function. The structure of these molecules may be considered at any of several length scales ranging from the level of individual atoms to the relationships among entire protein subunits. This useful distinction among scales is often expressed as a decomposition of molecular structure into four levels: primary, secondary, tertiary, and quaternary. The scaffold for this multiscale organization of the molecule arises at the secondary level, where the fundamental structural elements are the molecule's various hydrogen bonds.
In biology, the nuclear matrix is the network of fibres found throughout the inside of a cell nucleus and is somewhat analogous to the cell cytoskeleton. However, in contrast to the cytoskeleton, the nuclear matrix has been proposed to be a highly dynamic structure, perhaps more like a dynamic sponge with open compartments for free diffusion of molecules in the nucleus. The nuclear matrix, along with the nuclear lamina aid in organizing the genetic information within the cell.
In protein folding, a native contact is a contact between the side chains of two amino acids that are not neighboring in the amino acid sequence (i.e., they are more than four residues apart in the primary sequence in order to remove trivial i to i+4 contacts along alpha helices) but are spatially close in the protein's native state tertiary structure. The fraction of native contacts reproduced in a particular structure is often used as a reaction coordinate for measuring the deviation from the native state of structures produced during molecular dynamics simulations or in benchmarks of protein structure prediction methods.
chromatin structuresex chromatinnuclear chromatin
Chromatin is a complex of DNA and protein found in eukaryotic cells. Its primary function is packaging very long DNA molecules into a more compact, denser shape, which prevents the strands from becoming tangled and plays important roles in reinforcing the DNA during cell division, preventing DNA damage, and regulating gene expression and DNA replication. During mitosis and meiosis, chromatin facilitates proper segregation of the chromosomes in anaphase; the characteristic shapes of chromosomes visible during this stage are the result of DNA being coiled into highly condensed networks of chromatin.
The contact order of a protein is a measure of the locality of the inter-amino acid contacts in the protein's native state tertiary structure. It is calculated as the average sequence distance between residues that form native contacts in the folded protein divided by the total length of the protein. Higher contact orders indicate longer folding times, and low contact order has been suggested as a predictor of potential downhill folding, or protein folding that occurs without a free energy barrier. This effect is thought to be due to the lower loss of conformational entropy associated with the formation of local as opposed to nonlocal contacts.
nuclear membraneinner membraneperinuclear space
The nuclear envelope, also known as the nuclear membrane, is made up of two lipid bilayer membranes which in eukaryotic cells surrounds the nucleus, which encases the genetic material.
mutation studiesphi valuestransition state
Phi value analysis, \phi analysis, or \phi-value analysis is an experimental protein engineering technique for studying the structure of the folding transition state of small protein domains that fold in a two-state manner. The structure of the folding transition state is hard to find using methods like protein NMR or X-ray crystallography because folding transitions states are mobile and partly unstructured by definition. In \phi-value analysis, the folding kinetics and conformational folding stability of the wild-type protein are compared with those of point mutants to find phi values.
C-terminalC-terminal domainC terminus
The C-terminus (also known as the carboxyl-terminus, carboxy-terminus, C-terminal tail, C-terminal end, or COOH-terminus) is the end of an amino acid chain (protein or polypeptide), terminated by a free carboxyl group (-COOH). When the protein is translated from messenger RNA, it is created from N-terminus to C-terminus. The convention for writing peptide sequences is to put the C-terminal end on the right and write the sequence from N- to C-terminus.
A disease is a particular abnormal condition that negatively affects the structure or function of part or all of an organism, and that is not due to any external injury. Diseases are often known to be medical conditions that are associated with specific symptoms and signs. A disease may be caused by external factors such as pathogens or by internal dysfunctions. For example, internal dysfunctions of the immune system can produce a variety of different diseases, including various forms of immunodeficiency, hypersensitivity, allergies and autoimmune disorders.
CADASIL syndromeCerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathyCerebral arteriopathy with subcortical infarcts and leukoencephalopathy
CADASIL or CADASIL syndrome, involving cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy, is the most common form of hereditary stroke disorder, and is thought to be caused by mutations of the Notch 3 gene on chromosome 19. The disease belongs to a family of disorders called the leukodystrophies. The most common clinical manifestations are migraine headaches and transient ischemic attacks or strokes, which usually occur between 40 and 50 years of age, although MRI is able to detect signs of the disease years prior to clinical manifestation of disease.
A fibroblast is a type of biological cell that synthesizes the extracellular matrix and collagen, produces the structural framework (stroma) for animal tissues, and plays a critical role in wound healing. Fibroblasts are the most common cells of connective tissue in animals.
Muscle is a soft tissue found in most animals. Muscle cells contain protein filaments of actin and myosin that slide past one another, producing a contraction that changes both the length and the shape of the cell. Muscles function to produce force and motion. They are primarily responsible for maintaining and changing posture, locomotion, as well as movement of internal organs, such as the contraction of the heart and the movement of food through the digestive system via peristalsis.
In biology, the extracellular matrix (ECM) is a three-dimensional network of extracellular macromolecules, such as collagen, enzymes, and glycoproteins, that provide structural and biochemical support of surrounding cells. Because multicellularity evolved independently in different multicellular lineages, the composition of ECM varies between multicellular structures; however, cell adhesion, cell-to-cell communication and differentiation are common functions of the ECM.
GlnL-glutamine L -glutamine
Glutamine (symbol Gln or Q) is an α-amino acid that is used in the biosynthesis of proteins. Its side chain is similar to that of glutamic acid, except the carboxylic acid group is replaced by an amide. It is classified as a charge-neutral, polar amino acid. It is non-essential and conditionally essential in humans, meaning the body can usually synthesize sufficient amounts of it, but in some instances of stress, the body's demand for glutamine increases, and glutamine must be obtained from the diet. It is encoded by the codons CAA and CAG.
Lysine (symbol Lys or K) is an α-amino acid that is used in the biosynthesis of proteins. It contains an α-amino group (which is in the protonated −NH 3 + form under biological conditions), an α-carboxylic acid group (which is in the deprotonated −COO − form under biological conditions), and a side chain lysyl ((CH 2 ) 4 NH 2 ), classifying it as a basic, charged (at physiological pH), aliphatic amino acid. It is encoded by the codons, AAA and AAG. Like almost all other amino acids, the α-carbon is chiral and lysine may refer to either enantiomer or a racemic mixture of both.
Collagen is the main structural protein in the extracellular matrix in the various connective tissues in the body. As the main component of connective tissue, it is the most abundant protein in mammals, making up from 25% to 35% of the whole-body protein content. Collagen consists of amino acids bound together to form a triple helix of elongated fibril known as a collagen helix. It is mostly found in fibrous tissues such as tendons, ligaments, and skin.
Polyomaviridae is a family of viruses whose natural hosts are primarily mammals and birds. As of the most recent (2018) taxonomy release by the International Committee on Taxonomy of Viruses, there were 89 recognized species in this family contained within four genera, as well as 9 species that could not be assigned to a genus. Of these, 13 species are known to infect humans, whereas, to a lesser extent, other species, such as Simian Virus 40, have been identified in humans. Most of these viruses are very common and typically asymptomatic in most human populations studied.
Love styleslove stylelove traits
The color wheel theory of love is an idea created by Canadian psychologist John Alan Lee that describes six styles of love, using several of the Latin and Greek words for love. First introduced in his book Colours of Love: An Exploration of the Ways of Loving (1973), Lee defines three primary, three secondary and nine tertiary love styles, describing them in terms of the traditional color wheel. The three primary types are eros, ludus and storge, and the three secondary types are mania, pragma and agape.
Ankyrin repeat and BTB/POZ domain-containing protein 1 is a protein that in humans is encoded by the ABTB1 gene. This gene encodes a protein with an ankyrin repeat region and two BTB/POZ domains, which are thought to be involved in protein-protein interactions. Expression of this gene is activated by the phosphatase and tensin homolog, a tumor suppressor. Alternate splicing results in three transcript variants encoding different isoforms. * *
In molecular biology, transformation is the genetic alteration of a cell resulting from the direct uptake and incorporation of exogenous genetic material from its surroundings through the cell membrane(s). For transformation to take place, the recipient bacteria must be in a state of competence, which might occur in nature as a time-limited response to environmental conditions such as starvation and cell density, and may also be induced in a laboratory.