某些植物、昆虫和动物制造抗冻蛋白从而在冰点以下的温度中生存，一项研究帮助解释了某些最强大的天然抗冻蛋白如何工作。Konrad Meister及其同事把他们的研究重点放在了火红色的加拿大拟步甲虫（Dendroides canadensis）上，这种甲虫的过冬幼虫会制造超活性的抗冻蛋白。这组作者使用一种称为太赫兹光谱的技术在分子水平上观察了这种幼虫的蛋白和水的动态。此前的分析已经确定了这些蛋白可以与冰晶体结合，降低这些晶体能够生长的最低温度。这组作者报告说，当水过量存在的时候，这种抗冻活性能够持续下去，这是由于被认为抑制了冰的形成的氢键结合的大范围延迟。此前的研究也发现了诸如雪蚤等其他一些生物制造具有不同生化结构的抗冻蛋白。这组作者提出，这两种截然不同的机制以不同的比例赋予了至少3大类抗冻蛋白的活性，这些抗冻蛋白是由某些昆虫、细菌、极地鱼类和其他能抵御极端寒冷的生物制造的。这组作者说，进化已经产生了两种在结构上有差别的解决方案从而帮助生物在冰点以下温度中生存。(生物谷Bioon.com)
doi: 10.1073/pnas.1214911110
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Long-range protein–water dynamics in hyperactive insect antifreeze proteins
Konrad Meistera, Simon Ebbinghausa, Yao Xub, John G. Dumanc, Arthur DeVriesd, Martin Gruebelee, David M. Leitnerb, and Martina Havenitha,1
Antifreeze proteins (AFPs) are specific proteins that are able to lower the freezing point of aqueous solutions relative to the melting point. Hyperactive AFPs, identified in insects, have an especially high ability to depress the freezing point by far exceeding the abilities of other AFPs. In previous studies, we postulated that the activity of AFPs can be attributed to two distinct molecular mechanisms: (i) short-range direct interaction of the protein surface with the growing ice face and (ii) long-range interaction by protein-induced water dynamics extending up to 20 Å from the protein surface. In the present paper, we combine terahertz spectroscopy and molecular simulations to prove that long-range protein–water interactions make essential contributions to the high antifreeze activity of insect AFPs from the beetle Dendroides canadensis. We also support our hypothesis by studying the effect of the addition of the osmolyte sodium citrate.
