Kun Hagit, Mastai Yitzhak
Department of Chemistry, Bar-Ilan University, Ramat-Gan 52900, Israel.
Biopolymers. 2007;88(6):807-14. doi: 10.1002/bip.20844.
In this work, we present a study on the antifreeze activity of short segments of a Type I antifreeze protein, instead of the whole protein. This approach simplifies the correlation between antifreeze protein characteristics, such as hydrophilicity/hydrophobicity, and the effect of these characteristics on the antifreeze mechanism. Three short polypeptides of Type I AFP have been synthesized. Their antifreeze activity and interactions with water and ice crystals have been analyzed by various techniques such as circular dichroism spectroscopy, X-ray diffraction, differential scanning calorimetry, and osmometry. It is shown that one short segment of Type I AFP has an antifreeze activity of about 60% of the native protein activity. In this work, we demonstrate that short segments of Type I AFPs possess nonzero thermal hysteresis and result in modifications in the growth habits and growth rates of ice. This approach enables the preparation of large quantities of short AFP segments at low cost with high antifreeze activity, and opens the possibility of developing the commercial potential of AFPs.
在这项工作中，我们对I型抗冻蛋白的短片段而非完整蛋白的抗冻活性进行了研究。这种方法简化了抗冻蛋白特性（如亲水性/疏水性）与这些特性对抗冻机制的影响之间的关联。已合成了三种I型抗冻蛋白的短多肽。通过圆二色光谱、X射线衍射、差示扫描量热法和渗透压测定法等各种技术分析了它们的抗冻活性以及与水和冰晶的相互作用。结果表明，I型抗冻蛋白的一个短片段具有约60%的天然蛋白活性的抗冻活性。在这项工作中，我们证明I型抗冻蛋白的短片段具有非零热滞效应，并导致冰的生长习性和生长速率发生改变。这种方法能够以低成本大量制备具有高抗冻活性的短抗冻蛋白片段，并开启了开发抗冻蛋白商业潜力的可能性。
