Coupe du roi bisection of proteins. Spontaneous tetramerization of two peptides that span the sequence of the rabbit uteroglobin monomer.
The study of dividing objects into isometric segments has yielded novel approaches to the synthesis of high-symmetry organic compounds. Reported herein is the first application of this concept to a protein, rabbit uteroglobin (UG). Bisection of UG into two identical homochiral segments led to the design of the heterodimeric 70mer peptide alpha(1,2)-S-S-alpha(3,4) that spans the sequence of the native UG monomer. The ability of this compound to form a globular 140mer tetramer consisting of two noncovalently bound heterodimers was assessed by ultracentrifugation at sedimentation equilibrium and by fluorescent spectroscopy. On the other hand, the monomeric peptides alpha(1,2)-SH and alpha(3,4)-SH were shown to selectively form the alpha(1,2)-S-S-alpha(3,4) heterodimer via spontaneous air oxidation in phosphate buffer at neutral pH.
Nicolás
Ernesto
E
Department of Organic Chemistry, Martí i Franquès 1, Universitat de Barcelona, Barcelona 08028, Spain. enicolas@ub.edu
Ferrer
Cristina
C
Taboada
Lorena
L
Giralt
Ernest
E
D000595:Amino Acid Sequence; D000818:Animals; D002942:Circular Dichroism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000737:chemistry; D017434:Protein Structure, Tertiary; D011817:Rabbits; D013050:Spectrometry, Fluorescence; D014461:Ultracentrifugation; D014598:Uteroglobin / Q000138:chemical synthesis / Q000737:chemistry*
D010446:Peptide Fragments; D014598:Uteroglobin