Metalloprotein is a generic term for a protein that contains a metal ion cofactor. A large proportion of all proteins are part of this category. For instance, at least 1000 human proteins (out of ~20,000) contain zinc-binding protein domains although there may be up to 3000 human zinc metalloproteins. Abundance It is estimated that approximately half of all proteins contain a metal. In another estimate, about one quarter to one third of all proteins are proposed to require metals to carry out their functions. Thus, metalloproteins have many different functions in cells, such as storage and transport of proteins, enzymes and signal transduction proteins, or infectious diseases. The abundance of metal binding proteins may be inherent to the amino acids that proteins use, as even artificial proteins without evolutionary history will readily bind metals.Most metals in the human body are bound to proteins. For instance, the relatively high concentration of iron in the human body is mostly due to the iron in hemoglobin. Coordination chemistry...

A metallophone is any musical instrument in which the sound-producing body is a piece of metal (other than a metal string), such as tuned metal bars, tubes, rods, bowls, or plates. Most frequently the metal body is struck to produce sound, usually with a mallet, but may also be activated by friction, keyboard action, or other means. Metallophones have been used in music in Asia for thousands of years. There are several different types used in Balinese and Javanese gamelan ensembles, including the gendér, gangsa and saron. These instruments have a single row of bars, tuned to the distinctive pelog or slendro scales, or a subset of them. The Western glockenspiel and vibraphone are also metallophones: they have two rows of bars, in an imitation of the piano keyboard, and are tuned to the chromatic scale. In music of the 20th century and beyond, the word metallophone is sometimes applied specifically to a single row of metal bars suspended over a resonator box. Metallophones tuned to the diatonic scale are often used in schools; Carl Orff used diatonic metallophones in several of his pieces, including his pedagogical Schulwerk. Metallophones with microtonal...

Gamelan () (Javanese: ꦒꦩꦼꦭꦤ꧀, Sundanese: ᮌᮙᮨᮜᮔ᮪, Balinese: ᬕᬫᭂᬮᬦ᭄) is the traditional ensemble music of the Javanese, Sundanese, and Balinese peoples of Indonesia, made up predominantly of percussive instruments. The most common instruments used are metallophones played by mallets and a set of hand-played drums called kendhang/Kendang, which register the beat. The kemanak (a banana-shaped idiophone) and gangsa (another metallophone) are commonly used gamelan instruments in Bali. Other...

Stibnite, sometimes called antimonite, is a sulfide mineral with the formula Sb2S3. This soft grey material crystallizes in an orthorhombic space group. It is the most important source for the metalloid antimony. The name is derived from the Greek στίβι stibi through the Latin stibium as the former name for the mineral and the element antimony. Structure Stibnite has a structure similar to that of arsenic trisulfide, As2S3. The Sb(III) centers, which are pyramidal and three-coordinate, are linked via bent two-coordinate sulfide ions. However, some studies suggest that the actual coordination polyhedra of antimony are SbS7, with (3+4) coordination at the M1 site and (5+2) at the M2 site. Some of the secondary bonds impart cohesion and are connected with packing. Stibnite is grey when fresh, but can turn superficially black due to oxidation in air. Properties The melting point of Sb2S3 is 823 K (550 °C; 1,022 °F). The band gap is 1.88 eV at room temperature and it is a photoconductor...

Heavy metals are generally defined as metals with relatively high densities, atomic weights, or atomic numbers. The criteria used, and whether metalloids are included, vary depending on the author and context. In metallurgy, for example, a heavy metal may be defined on the basis of density, whereas in physics the distinguishing criterion might be atomic number, while a chemist would likely be more concerned with chemical behaviour. More specific definitions have been published, but none of these have been widely accepted. The definitions surveyed in this article encompass up to 96 out of the 118 known chemical elements; only mercury, lead and bismuth meet all of them. Despite this lack of agreement, the term (plural or singular) is widely used in science. A density of more than 5 g/cm3 is sometimes quoted as a commonly used criterion and is used in the body of this article. The earliest known metals—common metals such as iron, copper, and tin, and precious metals such as silver, gold, and platinum—are heavy metals. From 1809 onward, light metals, such as magnesium, aluminium, and titanium, were discovered, as well as less well...

Heme, or haem (pronounced /hi:m/ HEEM), is a precursor to hemoglobin, which is necessary to bind oxygen in the bloodstream. Heme is biosynthesized in both the bone marrow and the liver.In biochemical terms, heme is a coordination complex "consisting of an iron ion coordinated to a porphyrin acting as a tetradentate ligand, and to one or two axial ligands." The definition is loose, and many depictions omit the axial ligands. Among the metalloporphyrins deployed by metalloproteins as prosthetic groups, heme is one of the most widely used and defines a family of proteins known as hemoproteins. Hemes are most commonly recognized as components of hemoglobin, the red pigment in blood, but are also found in a number of other biologically important hemoproteins such as myoglobin, cytochromes, catalases, heme peroxidase, and endothelial nitric oxide synthase.The word haem is derived from Greek αἷμα haima meaning "blood". Function Hemoproteins have diverse biological...

Hemoglobin (haemoglobin in British English), abbreviated Hb or Hgb, is the iron-containing oxygen-transport protein present in red blood cells (erythrocytes) of almost all vertebrates (the exception being the fish family Channichthyidae) as well as the tissues of some invertebrate animals. Hemoglobin in blood carries oxygen from the respiratory organs (lungs or gills) to the other tissues of the body, where it releases the oxygen to enable aerobic respiration which powers the animal's metabolism. A healthy human has 12 to 20 grams of hemoglobin in every 100 mL of blood. Hemoglobin is a metalloprotein and chromoprotein. In mammals, hemoglobin makes up about 96% of a red blood cell's weight excluding water, and around 35% of the total weight including water. Hemoglobin has an oxygen-binding capacity of 1.34 mL O2 per gram, which increases the total blood oxygen capacity seventy-fold compared to dissolved oxygen in blood plasma alone. The mammalian hemoglobin molecule can bind and transport up to four oxygen molecules.Hemoglobin also transports other gases. It carries off some of...

Native element minerals are those elements that occur in nature in uncombined form with a distinct mineral structure. The elemental class includes metals, intermetallic compounds, alloys, metalloids, and nonmetals. The Nickel–Strunz classification system also includes the naturally occurring phosphides, silicides, nitrides, carbides, and arsenides. Elements The following elements occur as native element minerals or alloys: Nickel–Strunz Classification -01- Native elements This list uses the Classification of Nickel–Strunz (mindat.org, 10 ed, pending publication). Abbreviations "*" – discredited (IMA/CNMNC status). "?" – questionable/doubtful (IMA/CNMNC status). "REE" – Rare-earth element (Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) "PGE" – Platinum-group element (Ru, Rh, Pd, Os, Ir, Pt) 03.C Aluminofluorides, 06 Borates, 08 Vanadates (04.H V[5,6] Vanadates), 09...

Germanium is a chemical element with the symbol Ge and atomic number 32. It is lustrous, hard-brittle, grayish-white and similar in appearance to silicon. It is a metalloid in the carbon group that is chemically similar to its group neighbors silicon and tin. Like silicon, germanium naturally reacts and forms complexes with oxygen in nature. Because it seldom appears in high concentration, germanium was discovered comparatively late in the discovery of the elements. Germanium ranks near fiftieth in relative abundance of the elements in the Earth's crust. In 1869, Dmitri Mendeleev predicted its existence and some of its properties from its position on his periodic table, and called the element ekasilicon. In 1886, Clemens Winkler at Freiberg University found the new element, along with silver and sulfur, in the mineral argyrodite. Winkler named the element after his country, Germany. Germanium is mined primarily from sphalerite (the primary ore of zinc), though germanium is also recovered commercially from silver, lead, and copper ores. Elemental germanium is used as a semiconductor in transistors and various other electronic devices. Historically...

Gendicine is a gene therapy medication used to treat patients with head and neck squamous cell carcinoma linked to mutations in the TP53 gene. It consists of recombinant adenovirus engineered to code for p53 protein (rAd-p53) and is manufactured by Shenzhen SiBiono GeneTech. Gendicine was the first gene therapy product to obtain regulatory approval for clinical use in humans after Chinese State Food and Drug Administration approved it in 2003. Mechanism of action Gendicine enters the tumour cells by way of receptor-mediated endocytosis and begins to over-express genes coding for the p53 protein needed to fight the tumour. Ad-p53 seems to act by stimulating the apoptotic pathway in tumour cells, which increases the expression of tumour suppressor genes and immune response factors (such as the ability of natural killer (NK) cells to exert "bystander" effects). It also decreases the expression of multi-drug resistance, vascular endothelial growth factor and matrix metalloproteinase-2 genes and blocking transcriptional survival signals. p53 mutation status of the tumour cells and response to Ad-p53 treatment...