60.鈣離子是與prothrombin何種結構結合後,而活化其凝血作用?
(A)γ–carboxyglutamate
(B)succinic acid
(C)lysine
(D)arginine
答案:登入後查看
統計: A(565), B(155), C(181), D(234), E(0) #3491728
統計: A(565), B(155), C(181), D(234), E(0) #3491728
詳解 (共 8 筆)
#6578679
分享一個通靈法 大家記不記得 Protamine 是以化學性拮抗作爲 Heparin 的解毒劑
化學性拮抗可以簡單想成正負相吸的概念
所以鈣離子是正離子 一定會去配對陰離子

看這張圖的右上方A區 Lysine 和 Arginine 都是正離子 所以先去掉
所以剩下(A)(B)都是酸 水解後會是陰離子 所以只能死亡二選一了
但看到 Succinic acid 時我想到它的兩個好朋友
一個是去極化型肌肉鬆弛劑 Succinylcholine
另一個是汞 砷 鉛的解毒劑 Succimer(Dimercaptosuccinic acid,DMSA)
感覺不太像是抗凝血這個單元的東西
所以只好猜(A)了!
ㅤㅤ
順便一提 正電的胺基酸和負電的胺基酸可以記起來 對藥分的某些題目是很有幫助的!
ㅤㅤ
ㅤㅤ
36
0
#6611988
Prothrombin經維生素K依賴的 γ-carboxylation 修飾,在 N 端區域生成 γ-carboxyglutamate (Gla) 殘基。這些 Gla 殘基帶有雙羧基,能高效螯合 Ca²⁺。
當Ca²⁺ 與 Gla 區結合後,會使prothrombin(II)改變構型,並能夠插入磷脂膜上,促進其活化成 thrombin(IIa),參與凝血。
7
0
#6565177
Redox Cycling of vitamin K
Vit K is an essential cofactor necessary for the posttranslational carboxylation of the glutamic acid residues on the N-terminal portions of the specific clotting factors (II, VII, IX, and X) and anticoagulant proteins, such as protein C.
The newly synthesized γ-carboxyglutamate chelates Ca2+, causing the conformational change, and then activates four clotting factors followed by the bound to negatively charged phospholipid membranes.
Vit K is an essential cofactor necessary for the posttranslational carboxylation of the glutamic acid residues on the N-terminal portions of the specific clotting factors (II, VII, IX, and X) and anticoagulant proteins, such as protein C.
The newly synthesized γ-carboxyglutamate chelates Ca2+, causing the conformational change, and then activates four clotting factors followed by the bound to negatively charged phospholipid membranes.
3
0
#7285897
不是哥們這題有訣竅
- 鈣離子 +2價,所以要兩個負電去搞 chelation
- 一個glutamate有一個負電大家都知道,再加一個carboxy剛好兩個
- 結案。
3
0