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Beta-lactoglobulin
β-Lactoglobulin (BLG) is the major whey protein of cow and sheep's milk (~3 g/L), and is also present in many other mammalian species; a notable exception being humans. Its structure, properties and biological role have been reviewed many times. BLG is considered to be a milk allergen. Function The major protein in whey is β-lactoglobulin, followed by α-lactalbumin (β-lactoglobulin ≈ 65%, α-lactalbumin ≈ 25%, serum albumin ≈ 8%, other ≈ 2%). β-lactoglobulin is a lipocalin protein, and can bind many hydrophobic molecules, suggesting a role in their transport. β-lactoglobulin has also been shown to be able to bind iron via siderophores and thus might have a role in combating pathogens. Upon ingestion BLG is able to shuttle complexed iron into human immune cells, thereby providing micronutrition to these cells and participating in immune tolerance. A homologue of β-lactoglobulin is lacking in human breast milk. Structure S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Whey Protein
Whey protein is a mixture of proteins isolated from whey, the liquid material created as a by-product of cheese production. The proteins consist of α-lactalbumin, β-lactoglobulin, serum albumin and immunoglobulins. Glycomacropeptide also makes up the third largest component but is not a protein. Whey protein is commonly marketed as a protein supplement, and various health claims have been attributed to it. A review published in 2010 in the European Food Safety Authority Journal concluded that the provided literature did not adequately support the proposed claims. For muscle growth, whey protein has been shown to be slightly better compared to other types of protein, such as casein or soy. Production of whey Whey is left over when milk is coagulated during the process of cheese production, and contains everything that is soluble from milk after the pH is dropped to 4.6 during the coagulation process. It is a 5% solution of lactose in water and contains the water soluble prote ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lipocalin
The lipocalins are a family of proteins which transport small hydrophobic molecules such as steroids, bilins, retinoids, and lipids and most lipocalins are also able to bind to complexed iron (via siderophores or flavonoids) as well as heme. They share limited regions of sequence homology and a common tertiary structure architecture. This is an eight stranded antiparallel beta barrel with a repeated + 1 topology enclosing an internal ligand binding site. These proteins are found in gram negative bacteria, vertebrate cells, and invertebrate cells, and in plants. Lipocalins have been associated with many biological processes, among them immune response, pheromone transport, biological prostaglandin synthesis, retinoid binding, and cancer cell interactions. Function Immune response Lipocalin proteins are important key players of nutritional immunity by withholding and sequestering micronutrients. They are thereby able to regulate inflammatory and detoxification processe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpha-lactalbumin
Lactalbumin, alpha-, also known as LALBA, is a protein that in humans is encoded by the ''LALBA'' gene. Overview α-Lactalbumin is a protein that regulates the production of lactose in the milk of almost all mammalian species. In primates, alpha-lactalbumin expression is upregulated in response to the hormone prolactin and increases the production of lactose. α-Lactalbumin forms the regulatory subunit of the lactose synthase (LS) heterodimer and β-1,4-galactosyltransferase (beta4Gal-T1) forms the catalytic component. Together, these proteins enable LS to produce lactose by transferring galactose moieties to glucose. As a multimer, alpha-lactalbumin strongly binds calcium and zinc ions and may possess bactericidal or antitumor activity. A folding variant of human alpha-lactalbumin that may form in acidic environments such as the stomach, called HAMLET, probably induces apoptosis in tumor and immature cells. The corresponding folding dynamics of alpha-lactalbumin is thus hi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Milk Skin
Milk skin or lactoderm refers to a sticky film of protein that forms on top of dairy milk and foods containing dairy milk (such as hot chocolate and some soups). Milk film can be produced both through conventional boiling and by microwaving the liquid, and as such can often be observed when heating milk for use in drinks such as drinking chocolate. It is caused by the denaturation of proteins such as beta-lactoglobulin (whey protein). The thickness of the skin varies dependent on a number of factors, including the temperature of the milk, the shape of the container, and the amount of milk in the container. When milk is boiled, soluble milk proteins are denatured and then coagulate with milk's fat and form a sticky film across the top of the liquid, which then dries by evaporation. The layer does not need to be discarded and can be consumed, as protein's nutritional value is unaffected by the denaturation process. Milk film is often considered to be desirable and is used in sever ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kinemage
A kinemage (short for kinetic image) is an interactive graphic scientific illustration. It often is used to visualize molecules, especially proteins although it can also represent other types of 3-dimensional data (such as geometric figures, social networks, or tetrahedra oRNA base composition. The kinemage system is designed to optimize ease of use, interactive performance, and the perception and communication of detailed 3D information. The kinemage information is stored in a text file, human- and machine-readable, that describes the hierarchy of display objects and their properties, and includes optional explanatory text. The kinemage format is a defined chemical MIME type of 'chemical/x-kinemage' with the file extension '.kin'. Early history Kinemages were first developed by David Richardson at Duke University School of Medicine, for the Protein Society's journal Protein Science that premiered in January 1992. For its first 5 years (1992–1996), each issue of Protein Scien ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monomer
In chemistry, a monomer ( ; ''mono-'', "one" + '' -mer'', "part") is a molecule that can react together with other monomer molecules to form a larger polymer chain or three-dimensional network in a process called polymerization. Classification Monomers can be classified in many ways. They can be subdivided into two broad classes, depending on the kind of the polymer that they form. Monomers that participate in condensation polymerization have a different stoichiometry than monomers that participate in addition polymerization: : Other classifications include: *natural vs synthetic monomers, e.g. glycine vs caprolactam, respectively *polar vs nonpolar monomers, e.g. vinyl acetate vs ethylene, respectively *cyclic vs linear, e.g. ethylene oxide vs ethylene glycol, respectively The polymerization of one kind of monomer gives a homopolymer. Many polymers are copolymers, meaning that they are derived from two different monomers. In the case of condensation polymerizations, the r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caseine
Casein ( , from Latin ''caseus'' "cheese") is a family of related phosphoproteins ( αS1, aS2, β, κ) that are commonly found in mammalian milk, comprising about 80% of the proteins in cow's milk and between 20% and 60% of the proteins in human milk. Sheep and buffalo milk have a higher casein content than other types of milk with human milk having a particularly low casein content. Casein has a wide variety of uses, from being a major component of cheese, to use as a food additive. The most common form of casein is sodium caseinate. In milk, casein undergoes phase separation to form colloidal casein micelles, a type of secreted biomolecular condensate. As a food source, casein supplies amino acids, carbohydrates, and two essential elements, calcium and phosphorus. Composition Casein contains a high number of proline amino acids which hinder the formation of common secondary structural motifs of proteins. There are also no disulfide bridges. As a result, it has relatively ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Milk Allergy
Milk allergy is an adverse immune reaction to one or more proteins in cow's milk. Among the possible symptoms is anaphylaxis, a potentially life-threatening condition that requires treatment with epinephrine, among other measures. However, symptoms may take hours to days to manifest, with symptoms including atopic dermatitis, inflammation of the esophagus, enteropathy involving the small intestine and proctocolitis involving the rectum and colon. In the United States, 90% of allergic responses to foods are caused by eight foods, and cow's milk is the most common. Recognition that a small number of foods are responsible for the majority of food allergies has led to requirements to prominently list these common allergens, including dairy, on food labels. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ELISA
The enzyme-linked immunosorbent assay (ELISA) (, ) is a commonly used analytical biochemistry assay, first described by Eva Engvall and Peter Perlmann in 1971. The assay uses a solid-phase type of enzyme immunoassay (EIA) to detect the presence of a ligand (commonly a protein) in a liquid sample using antibodies directed against the protein to be measured. ELISA has been used as a diagnostic tool in medicine, plant pathology, and biotechnology, as well as a quality control check in various industries. In the most simple form of an ELISA, antigens from the sample to be tested are attached to a surface. Then, a matching antibody is applied over the surface so it can bind the antigen. This antibody is linked to an enzyme and then any unbound antibodies are removed. In the final step, a substance containing the enzyme's substrate is added. If there was binding, the subsequent reaction produces a detectable signal, most commonly a color change. Performing an ELISA involves at least ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
EC Directive
A directive is a legal act of the European Union that requires member states to achieve a particular result without dictating the means of achieving that result. Directives first have to be enacted into national law by member states before their laws are ruling on individuals residing in their countries. Directives normally leave member states with a certain amount of leeway as to the exact rules to be adopted. Directives can be adopted by means of a variety of legislative procedures depending on their subject matter. The text of a draft directive (if subject to the co-decision process, as contentious matters usually are) is prepared by the Commission after consultation with its own and national experts. The draft is presented to the Parliament and the Council—composed of relevant ministers of member governments, initially for evaluation and comment and then subsequently for approval or rejection. Justification There are justifications for using a directive rather than a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ionic Strength
The ionic strength of a solution is a measure of the concentration of ions in that solution. Ionic compounds, when dissolved in water, dissociate into ions. The total electrolyte concentration in solution will affect important properties such as the dissociation constant or the solubility of different salts. One of the main characteristics of a solution with dissolved ions is the ionic strength. Ionic strength can be molar (mol/L solution) or molal (mol/kg solvent) and to avoid confusion the units should be stated explicitly. The concept of ionic strength was first introduced by Lewis and Randall in 1921 while describing the activity coefficients of strong electrolytes. Quantifying ionic strength The molar ionic strength, ''I'', of a solution is a function of the concentration of ''all'' ions present in that solution. :I = \begin\frac\end\sum_^ c_i z_i^ where one half is because we are including both cations and anions, ''c''i is the molar concentration of ion i (M, mol/L), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
