プロタミン 化学特性,用途語,生産方法
定義
多くの脊椎動物の精子核中に存在する一群の強塩基性タンパク質の総称．通常，DNAと結合してヌクレオプロタミンとして存在する．分子量4×103，構成アミノ酸の約70％ がアルギニンで，トリプトファン，含硫黄アミノ酸，酸性アミノ酸を含まない．pI10～12．水に可溶．熱によって凝固しない．含まれる塩基性アミノ酸の種類により，(1)モノプロタミン：アルギニンのみを含むもの(クルペイン，サルミンなど)，(2)ジプロタミン：アルギニン以外にリシンまたはヒスチジンを含むもの，(3)トリプロタミン：アルギニン，リシンおよびヒスチジンを含むもの(スツリン；チョウザメの精子核中に存在)に分類される．森北出版「化学辞典（第2版）
発見
27～65残基の長さで分子量は約4000～1万。等電点は水素イオン濃度指数（pH）10～12で、塩基性アミノ酸、とくにアルギニンが最高で88％と多く、しかも、4～6残基の塊になっていることが多い。貝類にはアルギニンよりもリジンのほうが多いプロタミンもある。プロタミン, 1874年スイスの生化学者ミーシャーJohann Friedrich Miescher（1844―1895）が膿汁(のうじゅう)中の核様物質からヌクレイン（リン酸を含む酸性の有機化合物で、その後にサケの精子などから発見され、1889年に核から発見された酸性物質ということから、核酸と名づけられた）とともに塩基性物質をみいだしてプロタミンと命名、1893年ドイツの生化学者コッセル（1910年ノーベル医学生理学賞受賞）が種々の魚類から調製した。
化学的特性
Water soluble, producing basic solu-
tions.
使用
Protamine from salmon has been used to avoid
in vitro AT complex formation in samples from dogs pre-treated with heparin. It has also been used to study the influences of external potential on adsorption of various proteins to a metal surface.
定義
protamine: Any of a group of proteinsof relatively low molecularweight found in association with thechromosomal DNA of vertebratesperm cells. They contain a singlepolypeptide chain comprising about67% arginine. Protamines are thoughtto protect and support the chromosomes.
一般的な説明
Protamines are proteins rich in cysteine and arginine. It possesses many phosphorylation sites. Salmon fish contains around 15 genes encoding protamine. It is found to be localized to the sperm head.
作用機序
Protamine sulfate has been approved in the United States as a specific antagonist to heparin since
1968. Protamines are an arginine-rich, highly basic group of simple proteins derived from
salmon sperm. The highly acidic heparin polysaccharides exhibit their anticoagulant activity through
binding to antithrombin III. Because of the basicity of protamine, heparin has an increased affinity
for protamine relative to antithrombin III. In fact, its binding affinity for protamine is so much greater
than that of antithrombin III that protamine actually will induce dissociation of the
heparin/antithrombin III complex. If protamine is administered in the absence of heparin, it can have
marked effects on coagulation. Protamine is not completely selective for heparin and, in vivo, also
interacts with fibrinogen, platelets, and other plasma proteins causing anticoagulation. For this
reason, use of the minimal amount of protamine necessary to antagonize heparin-associated
bleeding should be employed (usually 1 mg of protamine intravenously for every 100 U of heparin
remaining in the patient).
副作用
Anaphylaxis also has been associated with the use of protamine. Although development of protamine
anaphylaxis is not limited to diabetics, those patients with diabetes that have used protaminecontaining insulin (NPH or protamine zinc) do have a slightly increased risk of anaphylaxis. Some less common reactions to protamine include pulmonary vasoconstriction, hypotension, and thrombus
formation.
プロタミン 上流と下流の製品情報
原材料
準備製品