Characterisation of the isolated Che Y C-terminal fragment (79-129)
John Wiley & Sons, 1997
Online
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Zugriff:
To gain insight into how the three-dimensional structure, stability and folding of the protein Che Y are related to one another, we have performed a conformational analysis of a long fragment of this protein, encompassing its C-terminal 51 residues (79–129). This fragment consists of residues in the β-strands 4 and 5 and α-helices 4 and 5 of native Che Y. The study has been performed by two-dimensional NMR and far-ultraviolet circular dichroism in aqueous solution and in 30% (by vol.) trifluoroethanol/water at 273 K and 298 K. We observe little structure for this fragment in aqueous solution which could be due to low helical populations in the regions corresponding to helices 4 and 5. Within the limits of the residual helical structure experimentally detected, helix 4 appears to extend beyond the N-terminus observed in the native structure by over four residues belonging to the preceding loop. In 30% trifluoroethanol the helical content of both helices increase and helix 4 extends further to include the preceding β-strand 4. None of the long-range NOES present in native Che Y are observed under the explored experimental conditions. The conformational shifts of the Hα protons within the α-helices of fragment 79–129 are identical to those of shorter synthetic peptides corresponding to the isolated a-helices. Thus, the fragment 79–129 appears to behave as an open chain with low local helical populations. The very low intrinsic ability for structure formation displayed by this region of Che Y at pH 2.5 suggests that in the folded protein this region could be mainly stabilised by interactions with the N-terminal Che Y region. This is in accordance with the contact map of Che Y, which shows that the strongest non-local contacts of C-terminal residues are with residues of the N-terminal region, while those within the C-terminal region are very weak. More importantly, the relationship appears to be possibly extended to the folding properties of the protein, since the C-terminal region is not structurally formed in the ...
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Characterisation of the isolated Che Y C-terminal fragment (79-129)
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Autor/in / Beteiligte Person: | Bruix, M. ; Muñoz, Víctor ; Campos-Olivas, Ramón ; Del Bosque, José Ramón ; Serrano, Luis ; Rico, Manuel |
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Veröffentlichung: | John Wiley & Sons, 1997 |
Medientyp: | academicJournal |
ISSN: | 0014-2956 (print) |
DOI: | 10.1111/j.1432-1033.1997.0384a.x |
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