Arsenite binding to synthetic peptides: The effect of increasing length between two cysteines
Arsenite binding to synthetic peptides: The effect of increasing length between two cysteines
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DOI：
10.1002/jbt.20112
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发表时间：
2006-01-01
影响因子：
3.6
通讯作者：
Wallace, K
中科院分区：
文献类型：
--
作者：
Kitchin, KT;Wallace, K
我们利用放射性73as标记的亚砷酸盐和真空过滤方法测定了亚砷酸盐与8种合成肽的结合亲和力，这些合成肽长度从13到24个氨基酸不等，含有一个或两个半胱氨酸，中间有0-17个氨基酸分隔。8个多肽中有6个氨基酸序列高度相似，并且基于人雌激素受体α的激素结合位点的半胱氨酸含有区域（例如肽28的序列为LEGAWCGKGVEGTEHLYSMKCKNV）。两个半胱氨酸之间含有0 ~ 14个氨基酸的肽结合亚砷酸盐，其K-d值为2.7 ~ 20.1 uM， B-max值为36 ~ 103 nmol/mg蛋白质（0.083 ~ 0.19 nmol/nmol蛋白质）。因此，将中间氨基酸的数量从0增加到14，对亚砷酸盐的K-d值几乎没有影响，这是一个令人惊讶的发现。因此，这些肽在溶液中是柔性的，并且有效地含有对亚砷酸盐高亲和力的二硫醇结合位点。两个C被19个氨基酸隔开的肽17与亚砷酸盐结合，K-d为123 uM， B-max为41.8 nmol/mg。单硫醇肽19结合亚砷酸盐，K-d为124 μ m， B-max为26 nmol/mg蛋白。所有的实验结合曲线都很好地符合单位点结合模型。(c) 2006 Wiley期刊公司
We utilized radioactive 73As-labeled arsenite and vacuum filtration methodology to determine the binding affinity of arsenite to eight synthetic peptides ranging from 13 to 24 amino acids long and containing one or two cysteines separated by 0-17 intervening amino acids. Six of the eight peptides were highly similar in amino acid sequence and were based on cysteine containing regions of the hormone-binding site of the human estrogen receptor-alpha (e.g., the sequence of peptide 28 is LEGAWCGKGVEGTEHLYSMKCKNV). The peptides with 0-14 intervening amino acids between two cysteines bound arsenite with K-d values of 2.7-20.1 uM and with B-max values from 36 to 103 nmol/mg protein (from 0.083 to 0.19 nmol/nmol of protein). Thus, increasing the number of intervening amino acids from 0 to 14 made very little difference in the observed K-d values for arsenite, a surprising finding. Therefore, these peptides are flexible in solution and effectively contain a dithiol high affinity binding site for arsenite. Peptide 17 with two C separated by 19 amino acids bound arsenite with a K-d of 123 uM and a B-max of 41.8 nmol/mg. The monothiol peptide 19 bound arsenite with a K-d of 124 uM and a B-max of 26 nmol/mg protein. All experimental binding curves fit well to a one site binding model. (c) 2006 Wiley Periodicals, Inc.