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Hemopexin
Hemopexin (or haemopexin; Hpx; Hx), also known as beta-1B-glycoprotein, is a glycoprotein that in humans is encoded by the ''HPX'' gene and belongs to the hemopexin family of proteins. Hemopexin is the plasma protein with the highest binding affinity for heme. Hemoglobin ''itself'' circulating ''alone'' in the blood plasma (called ''free hemoglobin'', as opposed to the hemoglobin situated in and circulating with the red blood cell.) will soon be oxidized into met-hemoglobin which then further disassociates into ''free'' heme along with globin chain. The free heme will then be oxidized into free met-heme and sooner or later the hemopexin will come to bind free met-heme together, forming a complex of met-heme and hemopexin, continuing their journey in the circulation until reaching a receptor, such as CD91, on hepatocytes or macrophages within the spleen, liver and bone marrow. Hemopexin's arrival and subsequent binding to the free heme not only prevent heme's pro-oxidant and pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hemopexin Family
The hemopexin family is a family of evolutionarily related proteins. Hemopexin-like repeats occur in vitronectin and some matrix metalloproteinases family (matrixins). The HX repeats of some matrixins bind tissue inhibitor of metallopeptidases ( TIMPs). Hemopexin () is a serum glycoprotein that binds haem and transports it to the liver for breakdown and iron recovery, after which the free hemopexin returns to the circulation. Hemopexin prevents haem-mediated oxidative stress. Structurally hemopexin consists of two similar halves of approximately two hundred amino acid residues connected by a histidine-rich hinge region. Each half is itself formed by the repetition of a basic unit of some 35 to 45 residues. Hemopexin-like domains have been found in two other types of proteins, vitronectin, a cell adhesion and spreading factor found in plasma and tissues, and matrixins MMP-1, MMP-2, MMP-3, MMP-9, MMP-10, MMP-11, MMP-12, MMP-14, MMP-15 and MMP-16, members of the matrix metalloproteina ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intravascular Hemolysis
Intravascular hemolysis describes hemolysis that happens mainly inside the vasculature. As a result, the contents of the red blood cell are released into the general circulation, leading to hemoglobinemia and increasing the risk of ensuing hyperbilirubinemia. __TOC__ Mechanism Intravascular hemolysis is the state when the red blood cell ruptures as a result of the complex of complement autoantibodies attached (fixed) on the surfaces of RBCs attack and rupture RBCs' membranes, or a parasite such as Babesia exits the cell that ruptures the RBC's membrane as it goes. Upon RBC's rupture, components of which are released and circulating in the blood plasma. These components comprise hemoglobin and others. At this stage, the hemoglobin is called free hemoglobin. Free hemoglobin (also called naked hemoglobin) is the un-bound hemoglobin that is not enclosed in the red blood cell. The naked hemoglobin is devoid of its anti-oxidant sentries that are normally available within the RBC. Free hem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haptoglobin
Haptoglobin (abbreviated as Hp) is the protein that in humans is encoded by the ''HP'' gene. In blood plasma, haptoglobin binds with high affinity to ''free'' hemoglobin released from erythrocytes, and thereby inhibits its deleterious oxidative activity. Compared to Hp, hemopexin binds to ''free'' heme. The haptoglobin-hemoglobin complex will then be removed by the reticuloendothelial system (mostly the spleen). In clinical settings, the haptoglobin assay is used to screen for and monitor intravascular hemolytic anemia. In intravascular hemolysis, free hemoglobin will be released into circulation and hence haptoglobin will bind the hemoglobin. This causes a decline in haptoglobin levels. Function Hemoglobin that has been released into the blood plasma by damaged red blood cells has harmful effects. The ''HP'' gene encodes a preproprotein that is processed to yield both alpha and beta chains, which subsequently combines as a tetramer to produce haptoglobin. Haptoglobin function ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haptoglobin
Haptoglobin (abbreviated as Hp) is the protein that in humans is encoded by the ''HP'' gene. In blood plasma, haptoglobin binds with high affinity to ''free'' hemoglobin released from erythrocytes, and thereby inhibits its deleterious oxidative activity. Compared to Hp, hemopexin binds to ''free'' heme. The haptoglobin-hemoglobin complex will then be removed by the reticuloendothelial system (mostly the spleen). In clinical settings, the haptoglobin assay is used to screen for and monitor intravascular hemolytic anemia. In intravascular hemolysis, free hemoglobin will be released into circulation and hence haptoglobin will bind the hemoglobin. This causes a decline in haptoglobin levels. Function Hemoglobin that has been released into the blood plasma by damaged red blood cells has harmful effects. The ''HP'' gene encodes a preproprotein that is processed to yield both alpha and beta chains, which subsequently combines as a tetramer to produce haptoglobin. Haptoglobin function ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glycoprotein
Glycoproteins are proteins which contain oligosaccharide chains covalently attached to amino acid side-chains. The carbohydrate is attached to the protein in a cotranslational or posttranslational modification. This process is known as glycosylation. Secreted extracellular proteins are often glycosylated. In proteins that have segments extending extracellularly, the extracellular segments are also often glycosylated. Glycoproteins are also often important integral membrane proteins, where they play a role in cell–cell interactions. It is important to distinguish endoplasmic reticulum-based glycosylation of the secretory system from reversible cytosolic-nuclear glycosylation. Glycoproteins of the cytosol and nucleus can be modified through the reversible addition of a single GlcNAc residue that is considered reciprocal to phosphorylation and the functions of these are likely to be an additional regulatory mechanism that controls phosphorylation-based signalling. In contrast, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, responding to stimuli, providing structure to cells and organisms, and transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the nucleotide sequence of their genes, and which usually results in protein folding into a specific 3D structure that determines its activity. A linear chain of amino acid residues is called a polypeptide. A protein contains at least one long polypeptide. Short polypeptides, containing less than 20–30 residues, are rarely considered to be proteins and are commonly called peptides. The individual amino acid residues are bonded together by peptide bonds and adjacent amino acid residues. The sequence of amino acid residue ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ligand
In coordination chemistry, a ligand is an ion or molecule (functional group) that binds to a central metal atom to form a coordination complex. The bonding with the metal generally involves formal donation of one or more of the ligand's electron pairs, often through Lewis bases. The nature of metal–ligand bonding can range from covalent to ionic. Furthermore, the metal–ligand bond order can range from one to three. Ligands are viewed as Lewis bases, although rare cases are known to involve Lewis acidic "ligands". Metals and metalloids are bound to ligands in almost all circumstances, although gaseous "naked" metal ions can be generated in a high vacuum. Ligands in a complex dictate the reactivity of the central atom, including ligand substitution rates, the reactivity of the ligands themselves, and redox. Ligand selection requires critical consideration in many practical areas, including bioinorganic and medicinal chemistry, homogeneous catalysis, and environmental chemi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iron
Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in front of oxygen (32.1% and 30.1%, respectively), forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust. In its metallic state, iron is rare in the Earth's crust, limited mainly to deposition by meteorites. Iron ores, by contrast, are among the most abundant in the Earth's crust, although extracting usable metal from them requires kilns or furnaces capable of reaching or higher, about higher than that required to smelt copper. Humans started to master that process in Eurasia during the 2nd millennium BCE and the use of iron tools and weapons began to displace copper alloys, in some regions, only around 1200 BCE. That event is considered the transition from the Bronze Age to the Iron A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BACH1
Transcription regulator protein BACH1 is a protein that in humans is encoded by the ''BACH1'' gene. Function This gene encodes a transcription factor that belongs to the cap'n'collar type of basic region leucine zipper factor family (CNC-bZip). The encoded protein contains broad complex, tramtrack, bric-a-brac/poxvirus and zinc finger (BTB/POZ) domains, which is atypical of CNC-bZip family members. These BTB/POZ domains facilitate protein-protein interactions and formation of homo- and/or hetero-oligomers. The C-terminus of the protein is a leucine zipper of the bzip_maf family. When this protein forms a heterodimer with MafK, it functions as a repressor of Maf recognition element (MARE) and transcription is repressed. Multiple alternatively spliced transcript variants have been identified for this gene. Some exons of this gene overlap with some exons from the C21orf41 gene, which is transcribed in an opposite orientation to this gene but does not seem to encode a protein. See ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Angiotensin
Angiotensin is a peptide hormone that causes vasoconstriction and an increase in blood pressure. It is part of the renin–angiotensin system, which regulates blood pressure. Angiotensin also stimulates the release of aldosterone from the adrenal cortex to promote sodium retention by the kidneys. An oligopeptide, angiotensin is a hormone and a dipsogen. It is derived from the precursor molecule angiotensinogen, a serum globulin produced in the liver. Angiotensin was isolated in the late 1930s (first named 'angiotonin' or 'hypertensin') and subsequently characterized and synthesized by groups at the Cleveland Clinic and Ciba laboratories. Precursor and types Angiotensinogen Angiotensinogen is an α-2-globulin synthesized in the liver and is a precursor for angiotensin, but has also been indicated as having many other roles not related to angiotensin peptides. It is a member of the serpin family of proteins, leading to another name: Serpin A8, although it is not known to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anemia
Anemia or anaemia (British English) is a blood disorder in which the blood has a reduced ability to carry oxygen due to a lower than normal number of red blood cells, or a reduction in the amount of hemoglobin. When anemia comes on slowly, the symptoms are often vague, such as tiredness, weakness, shortness of breath, headaches, and a reduced ability to exercise. When anemia is acute, symptoms may include confusion, feeling like one is going to pass out, loss of consciousness, and increased thirst. Anemia must be significant before a person becomes noticeably pale. Symptoms of anemia depend on how quickly hemoglobin decreases. Additional symptoms may occur depending on the underlying cause. Preoperative anemia can increase the risk of needing a blood transfusion following surgery. Anemia can be temporary or long term and can range from mild to severe. Anemia can be caused by blood loss, decreased red blood cell production, and increased red blood cell breakdown. Causes o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beta-globin
Hemoglobin subunit beta (beta globin, β-globin, haemoglobin beta, hemoglobin beta) is a globin protein, coded for by the ''HBB'' gene, which along with alpha globin ( HBA), makes up the most common form of haemoglobin in adult humans, hemoglobin A (HbA). It is 147 amino acids long and has a molecular weight of 15,867 Da. Normal adult human HbA is a heterotetramer consisting of two alpha chains and two beta chains. HBB is encoded by the ''HBB'' gene on human chromosome 11. Mutations in the gene produce several variants of the proteins which are implicated with genetic disorders such as sickle-cell disease and beta thalassemia, as well as beneficial traits such as genetic resistance to malaria. At least 50 disease-causing mutations in this gene have been discovered. Gene locus HBB protein is produced by the gene ''HBB'' which is located in the multigene locus of β-globin locus on chromosome 11, specifically on the short arm position 15.4. Expression of beta globin and the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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