To investigate if this sequence divergence leads to significant differences in the tertiary structure of the Eh αβ-tubulin heterodimer, we have modeled αβ-tubulin heterodimer of Eh based on the crystal structure of mammalian tubulin.
The dissimilar side chains in the two proteins lead to differences in the manner in which the secondary structure elements pack against each other ultimately leading to differences in the tertiary structure.
It is thus speculated that there might be differences in the tertiary structure between human and equine plasminogen [ 19].
The new model reveals differences in the tertiary protein structures of the PA domain, β-hairpin arrangement and one of the putative Ca+2 replacement sites between CPLS and tomato subtilisin.
One can expect that differences in the tertiary structures between the four fold classes are reflected in the level of hydrophobic contacts, involving residues of the G1 group, and in particular in positions with a high topohydrophobic index (y1 = 1).
These may contribute to differences in the tertiary and quaternary structures for these enzymes, in particular the monomeric subunit structure for human and baboon CES2 [ 27] [RS Holmes, J Glenn, JL VandeBerg & LA Cox: Baboon carboxylesterases 1 and 2: sequences, structures and phylogenetic relationships with human and other primate carboxylesterases, unpublished].
Within the pH range 6.4 9.2 there is very little difference in the secondary and tertiary structures of the protein as evidenced from CD studies.
The twisted β-sheet motif of domain I possesses a notable difference in its tertiary structure when compared with the PV, HAV, and HRV 3C proteases which, in contrast, display a complete β-barrel in this domain.
There was no significant difference in the mean fluorescence intensity (MFI) of the tertiary isonitrile sugar pulsed cells and the control cells.
In each group, a remarkable difference in the activation free energies for various tertiary amines was noted with the values in ranging from 10 to 60 kcal/mol.
