| 摘要: |
| 本文借助差式扫描量热法(DSC)研究了降温速率(5、10、20、50、100 ℃ /min)和溶液浓度(0.5、1、2、3、4 mol/L)对L－赖氨酸、L－脯氨酸、甘氨酸和L－丝氨酸等典型氨基酸类保护剂热物性参数的影响。研究结果表明:溶液浓度对低温保护剂溶液热物性参数的影响比降温速率的影响更加显著；在低溶液浓度(0.5mol/L和１mol/L)条件下，L－脯氨酸的未冻水含量高于其它3种氨基酸，表明在低浓度溶液中，Ｌ－脯氨酸的结合水能力更强，在高溶液浓度(2mol/L 和3mol/L)条件下，L－赖氨酸的未冻水含量高于其它3种氨基酸，因为在相同浓度溶液中，Ｌ－赖氨酸官能团浓度高于其它3种氨基酸，且其分子链较长，官能团自键合概率低，对冰晶抑制效果更强，表现出更高的未冻水含量。 |
| 关键词: 热物性参数 差示扫描量热法 氨基酸类保护剂 抑制冰晶 未冻水含量 |
| DOI： |
| 投稿时间：2020-01-07 修订日期：2020-05-11
|
| 基金项目:国家自然科学基金(51576132)资助项目。 |
|
| Study on Freezing Characteristics of Amino Acid Protectors and the Mechanism of Ice Crystal Inhibition |
| Li Xin,Xu Yi |
| (Institute of Biothermal Science and Technology, University of Shanghai for Science and Technology) |
| Abstract: |
| The effects of cooling rates (5, 10, 20, 50, 100 ℃/min) and solution concentration (0.5, 1, 2, 3, 4 mol/L) on the thermo-physical parameters of typical amino acid aqueous solutions ，such as L-lysine, L-proline, glycine ，and L-serine, were investigated viadifferential scanning calorimetry ( DSC). The results indicated that the effect of solution concentration on thermos - physical parameters of cryoprotectant solution was more significant than that of the cooling rate. At low concentrations (0. 5 mol/L and 1 mol/L) ，the unfrozen water content of L-proline was higher than that of other three amino acids. This indicates that the water-binding capacity of L-proline was higher than that of other three amino acids in low concentration solution. At high concentrations ( 2 mol/L and 3 mol/L) , the unfrozen wa-ter content of L-lysine was higher than that of the other three amino acids. Given that the concentration of the L-lysine functional group is higher than the other three amino acids in the same concentration solution and the longer molecular chain thereof leads to a lower probabili-ty of self-bonding of the functional group, a higher unfrozen water content was exhibited in the solution system. |
| Key words: thermophysical parameters diferential scanning calorimetry (DSC) amino acid cryoprotectants ice crystals inhibition um-frozen water content |
