应《网络安全法》要求，自2017年10月1日起，未进行实名认证将不得使用互联网跟帖服务。为保障您的帐号能够正常使用，请尽快对帐号进行手机号验证，感谢您的理解与支持！

24小时热门版块排行榜    

CyRhmU.jpeg
小木虫论坛-学术科研互动平台 » 生物医药区 » 分子生物 » 综合其他 » Streptavidin（链抗生物素）的分子结构式是怎么样的？
31/1返回列表
查看: 1856  |  回复: 13
查看全部回帖@他人 存档 新回复提醒 (忽略) 收藏    在APP中查看
当前只显示满足指定条件的回帖，点击这里查看本话题的所有回帖

安蓉

木虫 (正式写手)

[交流] Streptavidin（链抗生物素）的分子结构式是怎么样的？

请教大家一个问题：我想用牛血清蛋白BSA改性AFM的探针针尖，除了化学改性的方法，还有其他方法吗？我找到一个方法如下：

“利用AFM 来测定配体-受体之间作用力的样品制备为例子，其过程大致如下：
配体必须固定于AFM 尖端。我们用链抗生物素对尖端进行功能化处理。将AFM 悬臂浸入乙酮 5 分钟，然后紫外线照射 15 分钟；在37 °C的湿润孵化器中，悬臂浸入一滴50 ml 生物素-BSA（牛血清蛋白），孵育过夜；用PBS 磷酸缓冲液（pH 7.4）洗三次，除去非结合蛋白；室温下悬臂浸入一滴50 ml 链抗生物素中，孵育 10 分钟，在碱性环境中，使BSA吸附于悬臂；悬臂使用前，用PBS再冲洗三次即可。总之，将特定的配体或者受体固定于悬臂探针表面，将与之对应的受体或者配体固定于基底表面。在悬臂探针表面与基底表面相接近或者分离的过程中，悬臂受到偏折，从而测得两个功能化表面之间的作用力。即配体-受体之间的作用力。”
但是我不知道它的原理是怎么样的？是不是利用链抗生物素先改性针尖，然后再用生物素去结合，然后把BSA的头露在外面呢？
谢谢大家的帮助
谢谢。
回复此楼

» 猜你喜欢

» 本主题相关商家推荐: (我也要在这里推广)

» 本主题相关价值贴推荐，对您同样有帮助:

» 抢金币啦！回帖就可以得到:

查看全部散金贴
1楼2012-12-11 19:27:56
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

Chengxm

至尊木虫 (职业作家)
★ ★ ★
安蓉(金币+1): 谢谢参与
安蓉: 金币+2 2012-12-13 13:01:43
biotin----Avidine?
赞一下 回复此楼
10楼2012-12-12 20:55:50
 已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

Chengxm

至尊木虫 (职业作家)
★ ★ ★ ★ ★
gyesang: 金币+1, 鼓励交流！ 2012-12-14 12:32:45
安蓉: 金币+4 2012-12-14 17:40:58
Biotin also known as vitamin H or coenzyme R,[2] is a water-soluble B-vitamin (vitamin B7).

It is composed of a ureido (tetrahydroimidizalone) ring fused with a tetrahydrothiophene ring. A valeric acid substituent is attached to one of the carbon atoms of the tetrahydrothiophene ring. Biotin is a coenzyme for carboxylase enzymes, involved in the synthesis of fatty acids, isoleucine, and valine, and in gluconeogenesis.

Avidin is a tetrameric or dimeric[1] biotin-binding protein produced in the oviducts of birds, reptiles and amphibians deposited in the whites of their eggs. In chicken egg white, avidin makes up approximately 0.05% of total protein (approximately 1.8 mg per egg). The tetrameric protein contains four identical subunits (homotetramer), each of which can bind to biotin (Vitamin B7, vitamin H) with a high degree of affinity and specificity. The dissociation constant of avidin is measured to be KD ≈ 10−15 M, making it one of the strongest known non-covalent bonds.[2]

In its tetrameric form, avidin is estimated to be between 66–69 kDa in size.[3] Ten percent of the molecular weight is attributed to carbohydrate content composed of four to five mannose and three N-acetylglucosamine residues.[4] The carbohydrate moieties of avidin contain at least three unique oligosaccharide structural types that are similar in structure and composition.[5]

Functional avidin is found only in raw egg, as the biotin avidity of the protein is destroyed by cooking. The natural function of avidin in eggs is not known, although it has been postulated to be made in the ovaduct as a bacterial growth-inhibitor, by binding biotin the bacteria need. As evidence for this, streptavidin, a loosely related protein with equal biotin affinity and a very similar binding site, is made by certain strains of Streptomyces bacteria, and is thought to serve to inhibit the growth of competing bacteria, in the manner of an antibiotic.[6]

A non-glycosylated form of avidin has been isolated from commercially prepared product; however, it is not conclusive as to whether the non-glycosylated form occurs naturally or is a product of the manufacturing process.[7]

200px-Biotin_structure_JA.png
赞一下 回复此楼
13楼2012-12-14 11:55:39
 已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖
相关版块跳转 我要订阅楼主 安蓉 的主题更新
31/1返回列表
普通表情 龙 兔 虎 猫 高级回复(可上传附件)
信息提示
关闭
请填处理意见
关闭