TY - JOUR
T1 - Hyperactive antifreeze proteins from longhorn beetles: Some structural insights
AU - Kristiansen, Erlend
AU - Wilkens, Casper
AU - Friis, Dennis Steven
AU - Lorentzen, Anders Blomkild
AU - Jenssen, Håvard
AU - Løbner-Olesen, Anders
AU - Ramløv, Hans
PY - 2012/11
Y1 - 2012/11
N2 - This study reports on structural characteristics of hyperactive antifreeze proteins (AFPs) from two species of longhorn beetles. In Rhagium mordax, eight unique mRNAs coding for five different mature AFPs were identified from cold-hardy individuals. These AFPs are apparently homologues to a previously characterized AFP from the closely related species Rhagium inquisitor, and consist of six identifiable repeats of a putative ice binding motif TxTxTxT spaced irregularly apart by segments varying in length from 13 to 20 residues. Circular dichroism spectra show that the AFPs from both species have a high content of β-sheet and low levels of α-helix and random coil. Theoretical predictions of residue-specific secondary structure locate these β-sheets within the putative ice-binding motifs and the central parts of the segments separating them, consistent with an overall β-helical structure with the ice-binding motifs stacked in a β-sheet on one side of the coil. Molecular dynamics models based on these findings show that these AFPs would be energetically stable in a β-helical conformation.
AB - This study reports on structural characteristics of hyperactive antifreeze proteins (AFPs) from two species of longhorn beetles. In Rhagium mordax, eight unique mRNAs coding for five different mature AFPs were identified from cold-hardy individuals. These AFPs are apparently homologues to a previously characterized AFP from the closely related species Rhagium inquisitor, and consist of six identifiable repeats of a putative ice binding motif TxTxTxT spaced irregularly apart by segments varying in length from 13 to 20 residues. Circular dichroism spectra show that the AFPs from both species have a high content of β-sheet and low levels of α-helix and random coil. Theoretical predictions of residue-specific secondary structure locate these β-sheets within the putative ice-binding motifs and the central parts of the segments separating them, consistent with an overall β-helical structure with the ice-binding motifs stacked in a β-sheet on one side of the coil. Molecular dynamics models based on these findings show that these AFPs would be energetically stable in a β-helical conformation.
U2 - 10.1016/j.jinsphys.2012.09.004
DO - 10.1016/j.jinsphys.2012.09.004
M3 - Journal article
C2 - 23000739
SN - 0022-1910
VL - 58
SP - 1502
EP - 1510
JO - Journal of Insect Physiology
JF - Journal of Insect Physiology
IS - 11
ER -