Persistence of the alpha-helix stop signal in the S-peptide in trifluoroethanol solutions.
Persistence of the alpha-helix stop signal in the S-peptide in trifluoroethanol solutions.
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三氟乙醇溶液中 S 肽中 α 螺旋终止信号的持续存在。
DOI:
10.1021/bi00438a050
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发表时间:
1989
期刊:
影响因子:
2.9
通讯作者:
Kallenbach,NR
中科院分区:
文献类型:
--
作者:
Nelson,JW;Kallenbach,NR
Department of Chemistry, New York University, New York, New York 10003 Received December 5, 1988; Revised Manuscript Received March 8, 1989 abstract:-Helix formation in the S-peptide (residues 1-19 of ribonuclease A) was studied in detail by use of two-dimensional nuclear magnetic resonance to monitor the effects of 2, 2, 2-trifluoroethanol (TFE) at 0 C and pH* 2.07. TFE stabilizes the S-peptide-helix. Helix formation by a particular amino acid was monitored by the chemical shifts of the C “, C $, and Cy protons while increasing the concentration of TFE: large changes in chemical shift of a particular residue indicate that it is induced to go helical, whereas small chemical shift changes indicate little helix formation. Residues Thr-3 to Met-13 undergo chemical shift changes consistent with helix formation, whereas the other residues do not. Earlier work [Kim, P. S., & Baldwin, R. L.(1984) Nature 307, 329-334] reported that residues Thr-3 to His-12 become helical in aqueous solution. The existence of a “helix stop signal” was inferred from this behavior. We thus conclude that this helix stop signal persists in TFE solutions. e S-peptide, residues 1-19 or 1-20 of RNase A, 1 forms an unusually stable-helix in aqueous solution (Brown & Klee, 1971). Extensive studies on analogues of the C-peptide, residues 1-13 of RNase A, have shown that the stability depends on the charges of the amino acid side chains and helix termini (Shoemaker et al., 1987, 1985). This has been termed the “charged-group effect" and is determined by measuring the helix stability as the charges of the titratable side chains are altered by changing the pH, as well as by chemically introducing or removing charged side chains. An NMR study indicated that only residues 3-12 of S-peptide-(l-20) become helical in aqueous solution (Kim & Baldwin, 1984). Because the last several residues of the S-peptide fail to become helical, they hypothesized the existence of a “helix stop signal" that terminates the helix near His-12. Standard helix-coil transition theory predicts that short helical segments are strongly cooperative and that, once nucleation is achieved, propagation of helix is facile.
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DOI:
--
发表时间:
1985
期刊:
The Journal of biological chemistry
影响因子:
--
作者:
Neufeld,G;Gospodarowicz,D
通讯作者:
Gospodarowicz,D
DOI:
10.1172/jci112649
发表时间:
1986
期刊:
The Journal of clinical investigation
影响因子:
--
作者:
E. Rupp;P. Cameron;C. Ranawat;J. Schmidt;E. Bayne
通讯作者:
E. Bayne
DOI:
--
发表时间:
1988
期刊:
影响因子:
--
作者:
S. Mori;F. Goto;K. Goto;S. Ohkawara;S. Maeda;K. Shimada;M. Yoshinaga
通讯作者:
M. Yoshinaga
影响因子:
4.4
作者:
A. Lindemann;D. Riedel;W. Oster;S. Meuer;D. Blohm;R. Mertelsmann;F. Herrmann
通讯作者:
F. Herrmann
影响因子:
64.5
作者:
J. C. Fearn;A. King
通讯作者:
A. King