Douglas F. Dyckes
University of Houston
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by Douglas F. Dyckes.
Journal of Molecular Biology | 1978
Thomas E. Creighton; Douglas F. Dyckes; R.C. Sheppard
Abstract The reduced fragment of pancreatic trypsin inhibitor lacking the six C-terminal residues, which is produced by cyanogen bromide cleavage, formed a seemingly random mixture of disulphide bonds under refolding conditions where normal pancreatic trypsin inhibitor refolds correctly and quantitatively. This illustrates the importance of the C-terminal residues in folding of the normal protein, the uniqueness of the normal folded conformation, and the apparently central role in protein folding of long-range interactions between residues distant in the primary structure. The intact polypeptide chain of reduced pancreatic trypsin inhibitor in which the methionine residue normally at position 52 had been converted to homoserine refolded slightly less readily than the normal reduced compound. This was observed to be due to an altered spectrum of single-disulphide intermediates: the normally predominant intermediate with the 30–51 disulphide bond was less stable by about 0.8 kcal/mol relative to the other normal single-disulphide intermediates. The other steps in refolding appeared to be normal, although the refolded protein was observed to be susceptible to an unexplained reaction with iodoacetate.
Journal of Molecular Biology | 1981
Thomas E. Creighton; Douglas F. Dyckes
Abstract The normal CH 2 CH 2 SCH 3 side-chain of Met52 of bovine pancreatic trypsin inhibitor was converted to CH 2 CH 2 S + (CH 3 ) 2 with methyl iodide. After unfolding and breakage of the three disulphide bonds, the reduced protein refolded some three to six times more slowly than unmodified bovine pancreatic trypsin inhibitor. This was shown to be due to the decreased occurrence of the normal one- and two-disulphide initial intermediates. Modifications of the Met52 side-chain suggest that it normally has an important conformational role in the initial stages of folding, participating in extensive hydrophobic interactions with other parts of the protein. This role is different from that in the final folded state, where modification produced no detectable change in stability.
Experimental Biology and Medicine | 1987
Kanjana Ganeshan; Michael O. Perlman; Janet M. Perlman; Martin L. Adamo; Robert L. Hazelwood; Douglas F. Dyckes
Abstract Binding isotherms were constructed for the binding of synthetic tetrapeptide and pentapeptide fragments to membranes prepared from chicken cerebellar tissue. Both the tetrapeptide (FMRFamide), which was originally isolated from ganglia of mollusks, and the pentapeptide (LPLRFamide) previously isolated from chicken brain are known to increase blood pressure and modulate brain neurons in rats. The C-terminal dipeptide sequences of the two peptides are identical and both show similarity to the dipeptide sequence established for the pancreatic polypeptide (PP) family. Specific high-affinity binding sites exist for the latter peptide, sites which are competed for (though with less affinity) by neuropeptide Y (NPY). Affinity for cerebellar membranes was virtually equivalent for the synthetic peptide LPLRFamide and FRMFamide; the binding affinities (IC50) of all fragments tested (C-terminal pentapeptides of avian PP and NPY, and FMRFamide and LPLRFamide) fell in the same approximate range. Since the N-terminal residues of FMRFamide and LPLRFamide are not homologous with equivalent residues of APP or NPY, our results indicate that only Arg-Tyr-NH2 or Arg-Phe-NH2 sequences are necessary for binding of the carboxy terminus peptides of the PP family. In this respect, these sequences are functionally equivalent.
Analytical Chemistry | 1984
David. Pilosof; Hee Yong. Kim; Douglas F. Dyckes; Marvin L. Vestal
Journal of the American Chemical Society | 1984
H. Y. Kim; D. Pilosof; Douglas F. Dyckes; Marvin L. Vestal
Journal of the American Chemical Society | 1988
Krystyna. Stachowiak; Cheryl. Wilder; Marvin L. Vestal; Douglas F. Dyckes
Journal of Mass Spectrometry | 1984
David. Pilosof; Hee‐Yong Kim; Marvin L. Vestal; Douglas F. Dyckes
Journal of Organic Chemistry | 1985
John S. McMurray; Douglas F. Dyckes
Endocrinology | 1983
Martin L. Adamo; Douglas F. Dyckes; Robert L. Hazelwood
Biochemistry | 1986
John S. McMurray; Douglas F. Dyckes
Collaboration
Dive into the Douglas F. Dyckes's collaboration.
University of Texas Health Science Center at San Antonio
View shared research outputs