| 영문 | myosin | 한글 | 굵은근육미세섬유, 미오신 |
|---|---|---|---|
| 설명 | 골격근 근육섬유 속의 근육원섬유는 굵은 잔섬유와 가는 잔섬유로 이루어지는데, 미오신은 굵은 잔섬유를 구성하는 근단백질의 40% 이상을 차지하는 글로불린 모양의 단백질이다. 거의 불용성에 가까운 젤을 형성하기 때문에 근육의 수축과 이완에 중요한 역할을 한다. 1942년에 센트죄르지가 발견하였다. 굵은 잔섬유는 직경 1~12nm, 길이 1.6μm로, 미오신분자가 중합되어 만들어졌으며, 두 개의 팽창된 머리부분을 갖고 있다. 근절(sarcomere: 근원섬유 중의 섬유 방향의 반복단위)의 굵은 잔섬유는 200~400개의 미오신 분자로 이루어져 있다. 분자량 50만, 길이 160nm, 지름 2nm의 성냥개비 모양의 구조이다. 분자량 21만 5000인 폴리펩티드 두개와 몇 개의 저분자량 단백질로 되어 있는데, 이것들이 올바르게 짝지어져야 비로소 생물활성이 나타나게 된다. |
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| Gm | an allotype marker on the heavy chains of immunoglobins |
|---|---|
| MYHC | heavy chain cardiac myosin |
| MYHCA | heavy chain cardiac myosin alpha |
| SMHC | smooth muscle heavy chain myosin |
| VH | variable domain of heavy chain; variable heavy chain |
| FLC | Free light chains |
|---|---|
| MHC | Myosin II heavy chain |
| MHC | Myosin heavy chain |
| MyHC | Myosin heavy chain |
| SM MHC | Smooth muscle myosin heavy chain |
| myosin heavy chains | The heavy chains of the muscle protein myosin. Each molecule of myosin is composed of two heavy chains and two pairs of light chains. The heavy chains have a molecular weight of about 230 kD and each heavy chain is associated with a dissimilar pair of light chains. (devlin, textbook of biochemistry: with clinical correlations, 3rd ed, p957) (12 Dec 1998) |
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| myosin heavy chain | <protein> See myosin: do not confuse with heavy meromyosin which is a subfragment of the heavy chain of myosin II. (18 Nov 1997) |
|---|---|
| markov chains | A stochastic process such that the conditional probability distribution for a state at any future instant, given the present state, is unaffected by any additional knowledge of the past history of the system. (12 Dec 1998) |
| myosin | <protein> A family of motor ATPases that interact with F actin filaments. An increasing number of different myosins are being described. (See myosin light chains, meromyosin.) Myosin I is a low molecular weight (111-128 kD) form found in protozoa Acanthamoeba and Dictyostelium) that does not self assemble and is found in the cytoplasm as a globular monomeric molecule that can associate with membranes and transport membrane vesicles along microfilaments. Brush border Myosin I is a single headed myosin found in the microvilli of vertebrate intestinal epithelial cells, linking the membrane to the microfilament core. There is a single heavy chain of 119 kD and multiple (3 or 4) calmodulin light chains. The heavy chain has a C terminal domain that binds to acidic phospholipids. Myosin II is the classical sarcomeric myosin that self assembles into bipolar thick filaments. Myosin II is a multimeric protein (440 kD) with two heavy chains (200 kD) and two pairs of light chains (17-22 kD) in each hexamer. Between species and tissues there are considerable variations in the properties of Myosin II (see myosin light chains, meromyosin). Cytoplasmic myosin II is a family of sarcomeric myosin like proteins, also hexameric, responsible for force generation by interaction with microfilaments. There are two heavy chains (up to 240 kD) and two pairs of light chains (15-20 kD), the self assembled filaments are shorter than those of the sarcomere. The MYO2 gene product is an unconventional myosin from yeast involved in polarized secretion. MYO2 may be similar to dilute myosin from mouse and p190 protein from vertebrate brain. Scallop myosin is directly calcium regulated (through regulatory and essential light chains) and is more similar to sarcomeric myosin than to the nonsarcomeric myosins. Smooth muscle myosin has two 200 kD heavy chains, two regulatory 20 kD light chains that can be phosphorylated, altering its binding to the heavy chains which induces a conformational change that renders the myosin active and two 17 kD light chains. (18 Nov 1997) |
| myosin atpase | <enzyme> An enzyme that catalyses the hydrolysis of myosin ATP in the presence of actin to form myosin ADP and orthophosphate. This reaction is the immediate source of free energy that drives muscle contraction. In the absence of actin, myosin atpase activity is low and requires calcium ions. Chemical name: Myosin ATP phosphohydrolase (actin-translocating) Registry number: EC 3.6.1.32 (12 Dec 1998) |
| myosin filament | One of the contractile elements in skeletal, cardiac, and smooth muscle fibres; in skeletal muscle, the filament is about 10 nm thick and 1.5 um long. (05 Mar 2000) |
| myosin light chain | <protein> The light chains of the muscle protein myosin. Each molecule of myosin is composed of two heavy chains and two pairs of light chains. The light chains have a molecular weight of about 20 kD and there is one dissimilar pair of light chains associated with each heavy chain. The proteins all have sequence homology to calmodulin, but not all with calcium binding activity. Several types are known: regulatory light chains (LC 2, DNTB light chains) probably regulate the ATPase activity of the heavy chain directly (through the binding of calcium) or indirectly (activating when they themselves are phosphorylated by myosin light chain kinase) and essential light chains (LC 1, LC 3, alkali light chains), which have a more subtle and apparently nonessential role. In molluscan muscle the EDTA light chains (similar to LC 2 from vertebrate muscle) confer calcium sensitivity on the myosin itself. The light chains are "calmodulin-like" proteins that bind calcium. Two of them can be removed easily, and two with difficulty. The light chains bind the heavy chains in the vicinity of the head groups of the myosin. (12 Dec 1998) |
| myosin light chain kinase | <enzyme> An enzyme that phosphorylates myosin light chains in the presence of ATP to yield myosin-light chain phosphate and ADP, and requires calcium and calmodulin. The 20-kD light chain is phosphorylated more rapidly than any other acceptor, but light chains from other myosins and myosin itself can act as acceptors. The enzyme plays a central role in the regulation of smooth muscle contraction. Chemical name: ATP:myosin-light-chain O-phosphotransferase Registry number: EC 2.7.1.117 (12 Dec 1998) |
| myosin subfragments | Parts of the myosin molecule resulting from cleavage by proteolytic enzymes (papain, trypsin, or chymotrypsin) at well-localised regions. Study of these isolated fragments helps to delineate the functional roles of different parts of myosin. Two of the most common subfragments are myosin s-1 and myosin s-2. S-1 contains the heads of the heavy chains plus the light chains and s-2 contains part of the double-stranded, alpha-helical, heavy chain tail (myosin rod). (12 Dec 1998) |
| subfragment 1 of myosin | See: S1. (18 Nov 1997) |
| gene rearrangement, b-lymphocyte, heavy chain | Ordered rearrangement of b-lymphocyte variable gene regions thereby contributing to antibody diversity. It occurs during the first stage of differentiation of the immature b-lymphocyte. (12 Dec 1998) |
| metals, heavy | metals with high specific gravity, typically larger than 5. They have complex spectra, form coloured salts and double salts, have a low electrode potential, are mainly amphoteric, yield weak bases and weak acids, and are oxidizing or reducing agents (12 Dec 1998) |
| MyoD heavy chain kinase | <enzyme> Required for actin activation of the magnesium atpase activity of dictyostelium myosin id (myod); specific for myod Registry number: EC 2.7.1.- Synonym: 110-kD protein kinase, dictyostelium, dictyostelium 110-kD protein (26 Jun 1999) |
| heavy | 1. Heaved or lifted with labour; not light; weighty; ponderous; as, a heavy stone; hence, sometimes, large in extent, quantity, or effects; as, a heavy fall of rain or snow; a heavy failure; heavy business transactions, etc.; often implying strength; as, a heavy barrier; also, difficult to move; as, a heavy draught. 2. Not easy to bear; burdensome; oppressive; hard to endure or accomplish; hence, grievous, afflictive; as, heavy yokes, expenses, undertakings, trials, news, etc. "The hand of the Lord was heavy upon them of Ashdod." (1 Sam. V. 6) "The king himself hath a heavy reckoning to make." (Shak) "Sent hither to impart the heavy news." (Wordsworth) "Trust him not in matter of heavy consequence." (Shak) 3. Laden with that which is weighty; encumbered; burdened; bowed down, either with an actual burden, or with care, grief, pain, disappointment. "The heavy [sorrowing] nobles all in council were." (Chapman) "A light wife doth make a heavy husband." (Shak) 4. Slow; sluggish; inactive; or lifeless, dull, inanimate, stupid; as, a heavy gait, looks, manners, style, and the like; a heavy writer or book. "Whilst the heavy plowman snores." (Shak) "Of a heavy, dull, degenerate mind." (Dryden) "Neither [is] his ear heavy, that it can not hear." (Is. Lix. 1) 5. Strong; violent; forcible; as, a heavy sea, storm, cannonade, and the like. 6. Loud; deep; said of sound; as, heavy thunder. "But, hark! that heavy sound breaks in once more." (Byron) 7. Dark with clouds, or ready to rain; gloomy; said of the sky. 8. Impeding motion; cloggy; clayey; said of earth; as, a heavy road, soil, and the like. 9. Not raised or made light; as, heavy bread. 10. Not agreeable to, or suitable for, the stomach; not easily digested; said of food. 11. Having much body or strength; said of wines, or other liquors. 12. With child; pregnant. Heavy artillery. <chemistry> See Metal. Heavy weight, in wrestling, boxing, etc, a term applied to the heaviest of the classes into which contestants are divided. Cf. Feather weight, under Feather. Heavy is used in composition to form many words which need no special explanation; as, heavy-built, heavy-browed, heavy-gaited, etc. Origin: OE. Hevi, AS. Hefig, fr. Hebban to lift, heave; akin to OHG. Hebig, hevig, Icel. Hofigr, hofugr. See Heave. Source: Websters Dictionary (01 Mar 1998) |
| heavy chain | <protein> In general, the larger polypeptide in a multimeric protein. Thus the immunoglobulin heavy chain is of 50 kD, the light chain of 22 kD, whereas in myosin the heavy chain is very much larger (220 kD) than the light chains (~20 kD). (18 Nov 1997) |
| heavy chain disease | A disorder of immunoglobulin synthesis in which large quantities of abnormal heavy chains are excreted in the urine. The amino acid sequences of the n- (amino-) terminal regions of these chains are normal, but they have a deletion extending from part of the variable domain through the first domain of the constant region, so that they cannot form cross-links to the light chains. The defect arises through faulty coupling of the variable (v) and constant (c) region genes. (12 Dec 1998) |
Synonyms : Myosin Heavy Chain, Heavy Chain, Myosin, Heavy Chains, Myosin
제품명 |
판매사 |
보험코드 | 성분/함량 | 구분/보험급여 |
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제품명 |
판매사 |
보험코드 | 성분/함량 | 구분/보험급여 |
|---|