Partial characterization of an antifreeze protein (CRY-c) from Cryobacterium psychrotolerans MLB-29 of Arctic glacier cryoconite

• Published in: Polar Science
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2021
• Subjects: Antifreeze protein; Arctic bacteria; Cryoconite; Glacier; nanoLC-ESI-MS/MS; Arctic; Svalbard; glacier; Polar Science
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=16496; http://id.nii.ac.jp/1291/00016367/

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.