Antifreeze proteins (AFPs) play important roles in the survival of microorganisms existing in the cold environment. One of the several AFPs from an Arctic glacier bacterial strain which in our previous study showed thermal hysteresis (TH) and ice recrystallization inhibition (IRI) activities has been characterized partially in the present study. The cry-c AFP from the Svalbard Arctic cryoconite strain Cry-c MLB-29 belonging to the genus Cryobacterium has been characterized by ESI-Q-TOF-MS that revealed its molecular mass as 22.14 kDa. Multi-enzymatic limited digestion and nano-LC-ESI-MS/MS analyses revealed 228 amino acid residues in 21 peptide fragments. First 20 amino acid residues of the N-terminus of cry-c AFP has been deduced. Glycine and alalnine-rich sequences and the NXS motifs in several peptide fragments have been found out. Selected peptide fragments of the AFP have been modeled by PEP-FOLD and the structure-function correlation discussed in view of its antifreeze property.

抗冻蛋白 (AFP) 在寒冷环境中微生物的生存中起着重要作用。来自北极冰川细菌菌株的几种 AFP 之一在我们之前的研究中显示出热滞后 (TH) 和冰重结晶抑制 (IRI) 活性，在本研究中已部分表征。来自斯瓦尔巴群岛北极冰尘菌 Cry-c MLB-29 的 Cry-c AFP，属于Cryobacterium属已通过 ESI-Q-TOF-MS 表征其分子量为 22.14 kDa。多酶有限消化和纳米 LC-ESI-MS/MS 分析揭示了 21 个肽片段中的 228 个氨基酸残基。已经推断出cry-c AFP N末端的前20个氨基酸残基。已经发现了富含甘氨酸和丙氨酸的序列以及几个肽片段中的 NXS 基序。AFP 的选定肽片段已通过 PEP-FOLD 建模，并根据其抗冻特性讨论了结构-功能相关性。