It suggested that heat induced a self-reassembly from [beta]-sheet to a-helix
and [beta]-turn structure, as [beta]-sheet structure was always found in the interior of the folded molecule, and partly loss of [beta]-sheet structure indicated exposure of hydrophobic sites of the protein that may cause an increase in surface hydrophobicity.
Although the changes of BSA secondary structure caused by DIO in the presence of [Co.sup.2+] or [Zn.sup.2+] were different from those without metal ions, they all major led to the decrease of a-helix
First, the side chain R group is distributed in the outside of the main chain of a-helix
structure, but the continuous large R groups can make a-helix
structure unstable, thereby disabling amino acids from forming a-helix
H168, located in the middle of the a-helix
is of particular interest for the Cry1Aa toxin function because substituting H168 with Q, N, or R had different effects on toxicity.
CD data indicated secondary structural changes, with the primary changes occurring in the a-helix
. Freeze-drying the samples minimized structural changes during their storage.
As can beseen in Table 3, the secondary structure element content of CRL7 without treatment of organic solvent and ionic liquids was a-helix
: 43.46%, [beta]-sheet: 26.91%, [beta]-turn: 11.83%, and random coli: 17.79%, respectively.
In this last model, virtually the whole toxin, when associated with BBMV, is protected from proteinase K, with the exception that (in Cry1A toxins) a-helix
1 is cleaved off of the inserted form.