scholarly journals Amide proton exchange rates of oxidized and reduced saccharomyces cerevisiae iso-1-cytochrome c

1993 ◽  
Vol 2 (11) ◽  
pp. 1966-1974 ◽  
Author(s):  
Jennifer L. Marmorino ◽  
Douglas S. Auld ◽  
Stephen F. Betz ◽  
Donald F. Doyle ◽  
Gregory B. Young ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cytochrome C ◽  
Exchange Rates ◽  
Proton Exchange ◽  
Amide Proton ◽  
Amide Proton Exchange

Effect of peptide binding on amide proton exchange rates in the PDZ2 domain from human phosphatase hPTP1E

1998 ◽  
Vol 76 (2-3) ◽  
pp. 334-340 ◽  
Author(s):  
Irena Ekiel ◽  
Denis Banville ◽  
Shi Hsiang Shen ◽  
Kalle Gehring
Keyword(s):  
Exchange Rates ◽  
Ph Dependence ◽  
Guanidine Hydrochloride ◽  
Peptide Binding ◽  
Fluorescence Emission ◽  
Proton Exchange ◽  
Amide Proton ◽  
Amide Proton Exchange ◽  
C Terminus ◽  
Amide Exchange

Amide hydrogen-deuterium exchange rates were measured in the PDZ2 domain from human phosphatase hPTP1E by 1H-15N heteronuclear NMR spectroscopy. Protection factors were calculated for the slowly exchanging hydrogens in both the free PDZ2 domain and its complex with an octapeptide peptide, R-N-E-I-Q-S-L-V, derived from the C-terminus of the Fas receptor. Aside from a short α-helical region α1 (amino acids A-45 to D-49), the pattern of highly protected amides correlated well with the presence of hydrogen bonds in elements of the secondary structure. Hydrogen-bonded amides showed relatively fast exchange rates with half-lives of less than 9 h at pD 7.6 and 8°C. Protection factors, calculated as the ratio of theoretical (denatured) and observed exchange rates, showed less dispersion in maximal values than did the actual exchange rates. This behavior and the large pH dependence of the exchange rates suggest that amide exchange is close to the EX2 limit. In this limit, exchange of the most protected amides occurs through a global unfolding mechanism. The free energy of the unfolding calculated from the largest protection factors is 4.8 ± 0.4 kcal/mol (1 cal = 4.184 J). This ΔG° closely matches the value measured by experiments with guanidine hydrochloride and fluorescence emission spectroscopy. Peptide binding to PDZ2 resulted in mostly global effects and stabilized the folded domain by 1.4 kcal/mol.Key words: PDZ2 from hPTP1E, amide exchange, ligand binding, NMR.

scholarly journals On the pH dependence of amide proton exchange rates in proteins

1995 ◽  
Vol 69 (2) ◽  
pp. 329-339 ◽  
Author(s):  
M.A. Eriksson ◽  
T. Härd ◽  
L. Nilsson
Keyword(s):  
Exchange Rates ◽  
Ph Dependence ◽  
Proton Exchange ◽  
Amide Proton ◽  
Amide Proton Exchange

Effects of denaturants on amide proton exchange rates: a test for structure in protein fragments and folding intermediates

Biochemistry ◽  
1986 ◽  
Vol 25 (6) ◽  
pp. 1428-1436 ◽  
Author(s):  
David Loftus ◽  
George O. Gbenle ◽  
Peter S. Kim ◽  
Robert L. Baldwin
Keyword(s):  
Exchange Rates ◽  
Proton Exchange ◽  
Amide Proton ◽  
Protein Fragments ◽  
Folding Intermediates ◽  
Amide Proton Exchange
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