Mirror image forms of snow flea antifreeze protein prepared by total chemical synthesis have identical antifreeze activities.
Mirror image forms of snow flea antifreeze protein prepared by total chemical synthesis have identical antifreeze activities.
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DOI：
10.1021/ja801352j
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发表时间：
2008-07-30
影响因子：
15
通讯作者：
Kent SB
中科院分区：
文献类型：
--
作者：
Pentelute BL;Gates ZP;Dashnau JL;Vanderkooi JM;Kent SB
最近发现的富含甘氨酸的雪蚤抗冻蛋白(SfAFP)与任何已知蛋白都没有序列同源性。这种有趣的蛋白质分子的实验结构还没有报道。本文报道了sfAFP镜像形式(即天然蛋白L-sfAFP和天然蛋白对映体d-sfAFP)的全化学合成。SfAFP预测的81个氨基酸残基的多肽链在第1、13、28和43位含有半胱氨酸残基，是由4个人工合成的多肽片段通过自然化学连接而成的。纯化后，将合成的全长多肽在4℃下折叠，形成含有两个二硫键的sfAFP蛋白。在冰重结晶抑制实验中，化学合成的sfAFP具有预期的抗冻活性。镜像d-sfAFP蛋白采用相同的合成策略，使用由d-氨基酸制成的多肽片段，具有相同但符号相反的CD光谱。正如预期的那样，d-sfAFP表现出与L-sfAFP相同的防冻性能，因为冰为sfAFP结合提供了一个无手性表面。对sfAFP的简便合成将有助于确定其分子结构，并系统地阐明这种独特蛋白质的抗冻性能的分子基础。
The recently discovered glycine-rich snow flea antifreeze protein (sfAFP) has no sequence homology with any known proteins. No experimental structure has been reported for this interesting protein molecule. Here we report the total chemical synthesis of the mirror image forms of sfAFP (i.e., l-sfAFP, the native protein, and d-sfAFP, the native protein’s enantiomer). The predicted 81 amino acid residue polypeptide chain of sfAFP contains Cys residues at positions 1, 13, 28, and 43 and was prepared from four synthetic peptide segments by sequential native chemical ligation. After purification, the full-length synthetic polypeptide was folded at 4 °C to form the sfAFP protein containing two disulfides. Chemically synthesized sfAFP had the expected antifreeze activity in an ice recrystallization inhibition assay. Mirror image d-sfAFP protein was prepared by the same synthetic strategy, using peptide segments made from d-amino acids, and had an identical but opposite-sign CD spectrum. As expected, d-sfAFP displays the same antifreeze properties as l-sfAFP, because ice presents an achiral surface for sfAFP binding. Facile synthetic access to sfAFP will enable determination of its molecular structure and systematic elucidation of the molecular basis of the antifreeze properties of this unique protein.
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影响因子：
56.9
作者：
DAWSON, PE;MUIR, TW;KENT, SBH
通讯作者：
KENT, SBH
影响因子：
64.8
作者：
KNIGHT, CA;DEVRIES, AL;OOLMAN, LD
通讯作者：
OOLMAN, LD
影响因子：
3.5
作者：
WEN, DY;LAURSEN, RA
通讯作者：
LAURSEN, RA
影响因子：
64.8
作者：
Liou, YC;Tocilj, A;Jia, ZC
通讯作者：
Jia, ZC
DOI：
10.1107/s0907444996014989
发表时间：
1997-05-01
期刊：
ACTA CRYSTALLOGRAPHICA SECTION D-BIOLOGICAL CRYSTALLOGRAPHY
影响因子：
--
作者：
Hung, LW;Kohmura, M;Kim, SH
通讯作者：
Kim, SH