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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. β-globin 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 Beta-globin 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 gl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HBE1
Hemoglobin subunit epsilon is a protein that in humans is encoded by the ''HBE1'' gene. Function The epsilon globin gene (HBE) is normally expressed in the embryonic yolk sac: two epsilon chains together with two zeta chains (an alpha-like globin) constitute the embryonic hemoglobin Hb Gower I; two epsilon chains together with two alpha chains form the embryonic Hb Gower II. Both of these embryonic hemoglobins are normally supplanted by fetal, and later, adult hemoglobin. The five beta-like globin genes are found within a 45 kb cluster on chromosome 11 in the following order: 5' - epsilon – gamma-G – gamma-A – delta – beta - 3'. See also *Hemoglobin * Human β-globin locus * Hemoglobin alpha chains (two genes, same sequence): ** ''HBA1'' ** ''HBA2 Hemoglobin, alpha 2 also known as ''HBA2'' is a gene that in humans codes for the alpha globin chain of hemoglobin. Function The human alpha globin gene cluster is located on chromosome 16 and spans about 30 kb, inc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glutamic Acid
Glutamic acid (symbol Glu or E; known as glutamate in its anionic form) is an α- amino acid that is used by almost all living beings in the biosynthesis of proteins. It is a non-essential nutrient for humans, meaning that the human body can synthesize enough for its use. It is also the most abundant excitatory neurotransmitter in the vertebrate nervous system. It serves as the precursor for the synthesis of the inhibitory gamma-aminobutyric acid (GABA) in GABAergic neurons. Its molecular formula is . Glutamic acid exists in two optically isomeric forms; the dextrorotatory -form is usually obtained by hydrolysis of gluten or from the waste waters of beet-sugar manufacture or by fermentation.Webster's Third New International Dictionary of the English Language Unabridged, Third Edition, 1971. Its molecular structure could be idealized as HOOC−CH()−()2−COOH, with two carboxyl groups −COOH and one amino group −. However, in the solid state and mildly acidic water s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Codon
Genetic code is a set of rules used by living cells to translate information encoded within genetic material (DNA or RNA sequences of nucleotide triplets or codons) into proteins. Translation is accomplished by the ribosome, which links proteinogenic amino acids in an order specified by messenger RNA (mRNA), using transfer RNA (tRNA) molecules to carry amino acids and to read the mRNA three nucleotides at a time. The genetic code is highly similar among all organisms and can be expressed in a simple table with 64 entries. The codons specify which amino acid will be added next during protein biosynthesis. With some exceptions, a three-nucleotide codon in a nucleic acid sequence specifies a single amino acid. The vast majority of genes are encoded with a single scheme (see the RNA codon table). That scheme is often called the canonical or standard genetic code, or simply ''the'' genetic code, though variant codes (such as in mitochondria) exist. History Efforts to understan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Point Mutation
A point mutation is a genetic mutation where a single nucleotide base is changed, inserted or deleted from a DNA or RNA sequence of an organism's genome. Point mutations have a variety of effects on the downstream protein product—consequences that are moderately predictable based upon the specifics of the mutation. These consequences can range from no effect (e.g. Synonymous substitution, synonymous mutations) to deleterious effects (e.g. frameshift mutations), with regard to protein production, composition, and function. Causes Point mutations usually take place during DNA replication. DNA replication occurs when one double-stranded DNA molecule creates two single strands of DNA, each of which is a template for the creation of the complementary strand. A single point mutation can change the whole DNA sequence. Changing one purine or pyrimidine may change the amino acid that the nucleotides code for. Point mutations may arise from spontaneous mutations that occur during DNA re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sickle Cell Disease
Sickle cell disease (SCD), also simply called sickle cell, is a group of inherited Hemoglobinopathy, haemoglobin-related blood disorders. The most common type is known as sickle cell anemia. Sickle cell anemia results in an abnormality in the oxygen-carrying protein haemoglobin found in red blood cells. This leads to the red blood cells adopting an abnormal sickle-like shape under certain circumstances; with this shape, they are unable to deform as they pass through Capillary, capillaries, causing blockages. Problems in sickle cell disease typically begin around 5 to 6 months of age. A number of health problems may develop, such as attacks of pain (known as a sickle cell crisis) in joints, anemia, swelling in the hands and feet, bacterial infections, dizziness and stroke. The probability of severe symptoms, including long-term pain, increases with age. Without treatment, people with SCD rarely reach adulthood but with good healthcare, median life expectancy is between 58 and 66 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bone Marrow Transplantation
Hematopoietic stem-cell transplantation (HSCT) is the transplantation of multipotent hematopoietic stem cells, usually derived from bone marrow, peripheral blood, or umbilical cord blood, in order to replicate inside a patient and produce additional normal blood cells. HSCT may be autologous (the patient's own stem cells are used), syngeneic (stem cells from an identical twin), or allogeneic (stem cells from a donor). It is most often performed for patients with certain cancers of the blood or bone marrow, such as multiple myeloma, leukemia, some types of lymphoma and immune deficiencies. In these cases, the recipient's immune system is usually suppressed with radiation or chemotherapy before the transplantation. Infection and graft-versus-host disease are major complications of allogeneic HSCT. HSCT remains a dangerous procedure with many possible complications; it is reserved for patients with life-threatening diseases. As survival following the procedure has increa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blood Transfusions
Blood transfusion is the process of transferring blood products into a person's circulation intravenously. Transfusions are used for various medical conditions to replace lost components of the blood. Early transfusions used whole blood, but modern medical practice commonly uses only components of the blood, such as red blood cells, plasma, platelets, and other clotting factors. White blood cells are transfused only in very rare circumstances, since granulocyte transfusion has limited applications. Whole blood has come back into use in the trauma setting. Red blood cells (RBC) contain hemoglobin and supply the cells of the body with oxygen. White blood cells are not commonly used during transfusions, but they are part of the immune system and also fight infections. Plasma is the "yellowish" liquid part of blood, which acts as a buffer and contains proteins and other important substances needed for the body's overall health. Platelets are involved in blood clotting, prev ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beta Thalassemia
Beta-thalassemia (β-thalassemia) is an genetic disorder, inherited hemoglobinopathy, blood disorder, a form of thalassemia resulting in variable outcomes ranging from clinically asymptomatic to severe anemia individuals. It is caused by reduced or absent synthesis of the HBB, beta chains of hemoglobin, the molecule that carries oxygen in the blood. Symptoms depend on the extent to which hemoglobin is deficient, and include anemia, pallor, Fatigue, tiredness, Splenomegaly, enlargement of the spleen, jaundice, and Gallstone, gallstones. In severe cases death ensues. Beta thalassemia occurs due to a mutation of the HBB gene leading to deficient production of the hemoglobin subunit Hemoglobin subunit beta, beta-globin; the severity of the disease depends on the nature of the mutation, and whether or not the mutation is Zygosity, homozygous. The body's inability to construct beta-globin leads to reduced or zero production of Hemoglobin A, adult hemoglobin thus causing anemia. The ot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetramer
A tetramer () (''tetra-'', "four" + '' -mer'', "parts") is an oligomer formed from four monomers or subunits. The associated property is called ''tetramery''. An example from inorganic chemistry is titanium methoxide with the empirical formula Ti(OCH3)4, which is tetrameric in solid state and has the molecular formula Ti4(OCH3)16. An example from organic chemistry is kobophenol A, a substance that is formed by combining four molecules of resveratrol. In biochemistry, it similarly refers to a biomolecule formed of four units, that are the same ( homotetramer), i.e. as in Concanavalin A or different ( heterotetramer), i.e. as in hemoglobin. Hemoglobin has 4 similar sub-units while immunoglobulins have 2 very different sub-units. The different sub-units may have each their own activity, such as binding biotin in avidin tetramers, or have a common biological property, such as the allosteric binding of oxygen Oxygen is a chemical element; it has chemical symbol, symbo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dimerization
In chemistry, dimerization is the process of joining two identical or similar molecular entities by bonds. The resulting bonds can be either strong or weak. Many symmetrical chemical species are described as dimers, even when the monomer is unknown or highly unstable. The term ''homodimer'' is used when the two subunits are identical (e.g. A–A) and ''heterodimer'' when they are not (e.g. A–B). The reverse of dimerization is often called dissociation. When two oppositely-charged ions associate into dimers, they are referred to as ''Bjerrum pairs'', after Danish chemist Niels Bjerrum. Noncovalent dimers Anhydrous carboxylic acids form dimers by hydrogen bonding of the acidic hydrogen and the carbonyl oxygen. For example, acetic acid forms a dimer in the gas phase, where the monomer units are held together by hydrogen bonds. Many OH-containing molecules form dimers, e.g. the water dimer. Dimers that form based on weak electrostatic interaction and/or van der Waals in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hemoglobin Subunit Alpha
Hemoglobin subunit alpha, Hemoglobin, alpha 1, is a hemoglobin protein that in humans is encoded by the ''HBA1'' gene. Gene The human alpha globin gene cluster located on chromosome 16 spans about 30 kb and includes seven loci: 5'- zeta - pseudozeta - mu - pseudoalpha-1 - alpha-2 - alpha-1 - theta - 3'. The alpha-2 (HBA2) and alpha-1 (HBA1; this gene) coding sequences are identical. These genes differ slightly over the 5' untranslated regions and the introns, but they differ significantly over the 3' untranslated regions. Protein Two alpha chains plus two beta chains constitute HbA, which in normal adult life accounts for about 97% of the total hemoglobin; alpha chains combine with delta chains to constitute HbA-2, which with fetal hemoglobin (HbF), composed of alpha and gamma chains, make up the remaining 3% of adult hemoglobin. Clinical significance Alpha thalassemias result from deletions of each of the alpha genes as well as deletions of both HBA2 and HBA1; some ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
