Purification and structural analysis of a type III antifreeze protein from the european eelpout Zoarces viviparus.
It has recently been reported that the eelpout Zoarces viviparus synthesizes a family of antifreeze proteins (AFP) similar in sequence to type III AFPs. A method has been set up to separate these antifreeze proteins from blood serum of this teleost species. A total of nine proteins with antifreeze activity have been isolated, several to a purity suited for NMR experiments. One of the proteins, Zvafp13, has been subject to partial structure determination by NMR. 1D- and 2D-H NMR analyses were carried out. In the 1D-experiments it was observed that the protein contained 28 slow-exchanging amides, suggesting a compact structure. The 2D-experiments were utilized to assign observed signals to specific amino acids. From TOCSY- and NOESY-experiments 35 out of a total of 66 amino acids were assigned. The amide exchange pattern, protein primary sequence, chemical shifts and NOE-cross-peaks between amides and -protons in the -sheets suggest that Zvafp13 structurally resembles the recombinant type III AFP rQAE m1.1.
Albers
C N
CN
Dept. Life Sciences and Chemistry, Roskilde University, Roskilde, Demark.
Bjørn-Mortensen
M
M
Hansen
P E
PE
Ramløv
H
H
Sørensen
T F
TF
D000577:Amides / Q000097:blood / Q000737:chemistry / Q000302:isolation & purification; D000595:Amino Acid Sequence; D000818:Animals; D021343:Antifreeze Proteins, Type III / Q000097:blood / Q000737:chemistry / Q000302:isolation & purification; D002845:Chromatography; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular; D010473:Perciformes / Q000097:blood*; D017434:Protein Structure, Tertiary
D000577:Amides; D021343:Antifreeze Proteins, Type III