Expression, folding, and thermodynamic properties of the bovine oxytocin-neurophysin precursor: relationships to the intermolecular oxytocin-neurophysin complex.


Abstract

Earlier thermodynamic studies of the intermolecular interactions between mature oxytocin and neurophysin, and of the effects of these interactions on neurophysin folding, raised questions about the intramolecular interactions of oxytocin with neurophysin within their common precursor. To address this issue, the disulfide-rich precursor of oxytocin-associated bovine neurophysin was expressed in Escherichia coli and folded in vitro to yield milligram quantities of purified protein; evidence of significant impediments to yield resulting from damage to Cys residues is presented. The inefficiency associated with the refolding of reduced mature neurophysin in the presence of oxytocin was found not to be alleviated in the precursor. Consistent with this, the effects of pH on the spectroscopic properties of the precursor and on the relative stabilities of the precursor and mature neurophysin to guanidine denaturation indicated that noncovalent intramolecular bonding between oxytocin and neurophysin in the precursor had only a small thermodynamic advantage over the corresponding bonding in the intermolecular complex. Loss of the principal interactions between hormone and protein, and of the enhanced stability of the precursor relative to that of the mature unliganded protein, occurred reversibly upon increasing the pH, with a midpoint at pH 10. Correlation of these results with evidence from NMR studies of structural differences between the precursor and the intermolecular complex, which persist beyond the pH 10 transition, suggests that the covalent attachment of the hormone in the precursor necessitates a conformational change in its neurophysin segment and leads to properties of the system that are distinct from those of either the liganded or unliganded mature protein. Study holds ProTherm entries: 5705, 5706, 5707, 5708, 5709, 5710, 5711, 5712 Extra Details: intermolecular interactions; precursor; stability;,conformational change

Submission Details

ID: pmZQAQhY

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:30 p.m.

Version: 1

Publication Details
Eubanks S;Lu M;Peyton D;Breslow E,Biochemistry (1999) Expression, folding, and thermodynamic properties of the bovine oxytocin-neurophysin precursor: relationships to the intermolecular oxytocin-neurophysin complex. PMID:10521260
Additional Information

Structure view and single mutant data analysis

Study data

No weblogo for data of varying length.
Colors: D E R H K S T N Q A V I L M F Y W C G P
 

Data Distribution

Studies with similar sequences (approximate matches)

Correlation with other assays (exact sequence matches)


Relevant PDB Entries

Structure ID Release Date Resolution Structure Title
2LBH 2012-04-04 Solution Structure of the Dimeric Form of a Unliganded Bovine Neurophysin, Minimized Average Structure
1L5C 2002-03-20 Solution Structure of the Monomeric Form of a Mutant Unliganded Bovine Neurophysin, 20 Structures
2LBN 2012-04-04 (Revised) Solution structure of the monomeric form of a mutant unliganded bovine neurophysin, 20 structures
1L5D 2002-03-20 Solution Structure of the Monomeric Form of a Mutant Unliganded Bovine Neurophysin, Minimized Average Structure
1XY1 1988-04-16 1.04 CRYSTAL STRUCTURE ANALYSIS OF DEAMINO-OXYTOCIN. CONFORMATIONAL FLEXIBILITY AND RECEPTOR BINDING
1XY2 1988-04-16 1.2 CRYSTAL STRUCTURE ANALYSIS OF DEAMINO-OXYTOCIN. CONFORMATIONAL FLEXIBILITY AND RECEPTOR BINDING
2HNU 2007-04-24 2.0 Crystal Structure of a Dipeptide Complex of Bovine Neurophysin-I
2HNV 2007-04-24 2.5 Crystal Structure of a Dipeptide Complex of the Q58V Mutant of Bovine Neurophysin-I
2HNW 2007-04-24 2.9 Crystal Structure of the F91STOP mutant of des1-6 Bovine Neurophysin-I, unliganded state

Relevant UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
91.1 Oxytocin-neurophysin 1 P01179 NEU1_RAT
93.6 Oxytocin-neurophysin 1 P13389 NEU1_SHEEP
100.0 Oxytocin-neurophysin 1 P01175 NEU1_BOVIN