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Human serum albumin is the version of serum albumin found in human blood. It is the most abundant protein in human blood plasma; it constitutes about half of serum protein. It is produced in the liver. It is soluble and monomeric. Albumin transports hormones, fatty acids, and other compounds, buffers pH, and maintains osmotic pressure, among other functions. Albumin is synthesized in the liver as preproalbumin, which has an N-terminal peptide that is removed before the nascent protein is released from the rough endoplasmic reticulum. The product, proalbumin, is in turn cleaved in the Golgi vesicles to produce the secreted albumin. The reference range for albumin concentrations in serum is approximately 35 - 50 g/L (3.5 - 5.0 g/dL). It has a serum half-life of approximately 20 days. It has a molecular mass of 66.5 kDa. The gene for albumin is located on chromosome 4 and mutations in this gene can result in anomalous proteins. The human albumin gene is 16,961 nucleotides long from the putative 'cap' site to the first poly(A) addition site. It is split into 15 exons that are symmetrically placed within the 3 domains thought to have arisen by triplication of a single primordial domain. == Function == * Maintains oncotic pressure * Transports thyroid hormones * Transports other hormones, in particular, ones that are fat-soluble * Transports fatty acids ("free" fatty acids) to the liver and to myocytes for utilization of energy * Transports unconjugated bilirubin * Transports many drugs; serum albumin levels can affect the half-life of drugs * Competitively binds calcium ions (Ca2+) * Buffers pH * Serum albumin, as a negative acute-phase protein, is down-regulated in inflammatory states. As such, it is not a valid marker of nutritional status; rather, it is a marker of an inflammatory state * Prevents photodegradation of folic acid 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Human serum albumin」の詳細全文を読む スポンサード リンク
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