TY - JOUR
T1 - Structural and dynamical comparison of α, β and γ forms of murine epidermal growth factor
AU - MAYO, Kevin H.
AU - BURKE, Carl
PY - 1987/11
Y1 - 1987/11
N2 - Reversed‐phase high‐performance liquid chromatography of mouse epidermal growth factor (mEGF) purified by the method of Savage and Cohen [1] allows resolution of four forms of the protein hormone: α, β, γ and δ. α‐mEGF, the major form isolated by HPLC, is the parent mEGF originally sequenced by Savage and Cohen [1], and β‐mEGF is des‐asparaginyl1‐α‐mEGF. Proton nuclear magnetic resonance spectroscopy has been used to investigate structural and dynamical differences among the α, β and γ forms of the peptide. Based on these data, γ‐mEGF can be tentatively identified as des‐Asn1, Ser2−mEGF. Comparative nuclear Overhauser experiments on amide and aromatic proton resonances suggest that there are significant conformational changes in the peptide structure on cleavage of the N‐terminal residues. Backbone amide proton/deuteron exchange rates in γ‐mEGF and β‐mEGF are significantly faster than those in α‐mEGF suggesting that structural dynamics are enhanced in the minor forms; this interpretation is supported by the decrease in Tyr(2,6)–(3,5) intraresidue NOE magnitudes on going from α to β to γ forms. These data suggest that the average conformations of β and γ‐mEGF favor a more open or denatured state of the protein and that the N terminus is critical to the structural integrity of the parent protein.
AB - Reversed‐phase high‐performance liquid chromatography of mouse epidermal growth factor (mEGF) purified by the method of Savage and Cohen [1] allows resolution of four forms of the protein hormone: α, β, γ and δ. α‐mEGF, the major form isolated by HPLC, is the parent mEGF originally sequenced by Savage and Cohen [1], and β‐mEGF is des‐asparaginyl1‐α‐mEGF. Proton nuclear magnetic resonance spectroscopy has been used to investigate structural and dynamical differences among the α, β and γ forms of the peptide. Based on these data, γ‐mEGF can be tentatively identified as des‐Asn1, Ser2−mEGF. Comparative nuclear Overhauser experiments on amide and aromatic proton resonances suggest that there are significant conformational changes in the peptide structure on cleavage of the N‐terminal residues. Backbone amide proton/deuteron exchange rates in γ‐mEGF and β‐mEGF are significantly faster than those in α‐mEGF suggesting that structural dynamics are enhanced in the minor forms; this interpretation is supported by the decrease in Tyr(2,6)–(3,5) intraresidue NOE magnitudes on going from α to β to γ forms. These data suggest that the average conformations of β and γ‐mEGF favor a more open or denatured state of the protein and that the N terminus is critical to the structural integrity of the parent protein.
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U2 - 10.1111/j.1432-1033.1987.tb13598.x
DO - 10.1111/j.1432-1033.1987.tb13598.x
M3 - Article
C2 - 3500044
AN - SCOPUS:0023657997
SN - 0014-2956
VL - 169
SP - 201
EP - 207
JO - European Journal of Biochemistry
JF - European Journal of Biochemistry
IS - 1
ER -