Adsorption of Biomolecules to Ice and Their Effects upon Ice Growth. 1. Measuring Adsorption Orientations and Initial Results
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- 作者：Charles A. Knight ; Andrzej Wierzbicki ; Richard A. Laursen ; and Wei Zhang
- 刊名：Crystal Growth & Design
- 出版年：2001
- 出版时间：November 2001
- 年：2001
- 卷：1
- 期：6
- 页码：429 - 438
- 全文大小：415K
- 年卷期：v.1,no.6(November 2001)
- ISSN：1528-7505
文摘
Different fish, insects, and plants have evolved a range of peptides and glycopeptides that adsorb toice from water solution and dramatically influence ice growth in ways that benefit the organisms. Understandingthe adsorption itself is fundamental but difficult to study experimentally. One fundamental attribute of the adsorptionis the orientation relationship between the adsorbing molecules and the ice surface. A method that has been usedto determine the ice interface orientations at which adsorption of AFs leads to engulfment into growing ice (Knight,C. A.; Cheng, C. C.; DeVries, A. L. Biophys. J. 1991, 59, 409-418) is extended here to reveal orientations at whichthe solute molecules are adsorbed but not engulfed. Adsorption without engulfment is found to be quite common,and some examples show a surprising sensitivity of adsorption of this kind to small changes of interface orientation.Solutes that prevent ice growth must adsorb permanently, fixed to the ice itself at the ice/water interface and unableto migrate with the interface. The new technique provides a way to detect adsorption that is either impermanent orallows the adsorbate to advance with the interface but does not distinguish between these two possibilities. Peptidesthat contain predominantly or exclusively lysine and alanine are used for this first study and demonstration of thetechnique. They all have a strong tendency to adsorb at {21
0}, secondary prism plane orientations, with alignmentdeduced to be approximately parallel to <012>. However, many of the materials examined here are not engulfedas the ice grows and do not stop ice crystal growth. Polymers and peptides of lysine and alanine could be an interesting,relatively simple system to study in a systematic way to elucidate the mechanisms of action of nonequilibriumantifreezes.
0}, secondary prism plane orientations, with alignmentdeduced to be approximately parallel to <012>. However, many of the materials examined here are not engulfedas the ice grows and do not stop ice crystal growth. Polymers and peptides of lysine and alanine could be an interesting,relatively simple system to study in a systematic way to elucidate the mechanisms of action of nonequilibriumantifreezes.