ISSN:
1432-136X
Keywords:
Antifreeze proteins
;
Thermal hysteresis proteins
;
Insect cold tolerance
;
Beetle Dendroides
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Summary Four antifreeze proteins (AFPs) were purified from larvae of the beetle Dendroides canadensis. The AFPs are similar in amino acid compositions, having high contents of hydrophilic amino acids (45–55 mol%) and cysteine (∼16 mol% Cys). Approximately half of the Cys residues form disulfide bridges, and both the disulfide bridges and free sulfhydryls are essential for activity. The N-terminals of the AFPs are blocked. The pH optimum of the AFPs is ∼7.8, but major loss of activity occurred only at very high pH (12.0). The detergents SDS and Triton X-100 did not inactivate the AFPs. Circular dichroism spectra indicate the presence of both α and β secondary structures in the AFPs, in addition to a large random structure component.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00262308
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