Covalent Structure of Bovine Neurophysin-II: Localization of the Disulfide Bonds
AUTOR(ES)
Schlesinger, D. H.
RESUMO
The completed amino-acid sequence of bovine neurophysin-II, a major neurohypophyseal hormone-binding protein in the hypothalamo-neurohypophyseal complex of cows, set the stage for the localization of the disulfide bonds of this sulfur-rich molecule. Neurophysin-II was digested with subtilisin or a pepsin-trypsin mixture. The resulting peptides were subjected to first-dimensional electrophoresis at pH 6.5, oxidized with performic acid, and subjected to second-dimensional electrophoresis under identical conditions as the first-dimensional separation, but in a perpendicular direction. Cysteic acid peptides were eluted (several after additional electrophoretic purification at pH 3.5) for amino-acid composition and NH2- and COOH-terminal analyses. Our assignment of the seven disulfide bridges present in neurophysin-II is as follows: Cys10-Cys93; Cys13-Cys95; Cys21-Cys27; Cys28-Cys44; Cys54-Cys61; Cys67-Cys73; Cys74-Cys79. The assignment of disulfide bridges associated with Cys27 and Cys28 is tentative as it is derived from evolutionary consideration. The high disulfide content reduces drastically the allowed number of biofunctional conformers of neurophysin-II. It is suggested that neurophysin-II possesses a globular topography with minimal α-helix structure.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=389769Documentos Relacionados
- Disulfide Bonds and the Quaternary Structure of Factor VIII/von Willebrand Factor
- Evolution of Neurophysin Proteins: The Partial Sequence of Bovine Neurophysin-I
- STRUCTURE OF FRAGMENTS OF ANTIBODY MOLECULES AS REVEALED BY REDUCTION OF EXPOSED DISULFIDE BONDS*
- Partial primary structure of the T4 antigens of mouse and sheep: assignment of intrachain disulfide bonds.
- Unsynchronized resonance of covalent bonds in the superconducting state
