Studies on dissociation of mouse prolactin from mouse hepatic receptors

• Published in: Molecular and cellular endocrinology Vol. 44; no. 2; pp. 159 - 164
• Main Authors: Haro, Luis S., Talamantes, Frank J.
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 01.02.1986; Elsevier
• Subjects: Animals; Anions; Biological and medical sciences; Cell Membrane - metabolism; Cell receptors; Cell structures and functions; dissociation kinetics; Female; Fundamental and applied biological sciences. Psychology; Hydrogen-Ion Concentration; Hydrophobic interactions; Kinetics; liver; Liver - metabolism; Mice; Molecular and cellular biology; mouse prolactin; negative cooperativity; Pregnancy; prolactin; Prolactin - metabolism; prolactin receptor; Receptors, Cell Surface - metabolism; Receptors, Prolactin; Thermodynamics; prolactin receptor; negative cooperativity; Hydrophobic interactions; mouse prolactin; dissociation kinetics; pregnancy; Liver; Rodentia; Metabolism; Molecular dissociation; Protein hormone; Vertebrata; Regulation(control); Mammalia; Mouse; Prolactin; Hormone receptor complex; Kinetics; Hormonal receptor
• ISSN: 0303-7207; 1872-8057
• DOI: 10.1016/0303-7207(86)90058-4

The influence of pH, temperature, ethylene glycol, urea, chaotropic anions and excess unlabelled secreted mouse prolactin (smPRL) on the dissociation kinetics of 125I-iodosmPRL from mouse hepatic receptors was investigated. The destabilization of smPRL-receptor complexes by chaotropic anions followed the typical trend of the Hofmeister series: I −> Br −> Cl −> F − . Increasing the temperature of the dissociation reaction from 8°C to 23°C and 30°C caused partial dissociation of 125I-iodosmPRL-receptor complexes. Dissociation of 125I-iodosmPRL from mouse hepatic receptors was pH dependent, with the slowest rate of dissociation occurring at pH 8 and the fastest rate of dissociation occurring at pH 5 and 6. Both ethylene glycol and urea accelerated the rate of dissociation of 125I-iodosmPRL from mouse hepatic receptors in a concentration-dependent manner. Dissociation of 125I-iodosmPRL from mouse hepatic receptors was 6-fold faster in the presence of excess unlabelled smPRL than in its absence. The results of these investigations suggest that both protonation/de-protonation reactions and hydrophobic interactions play important roles in stabilizing the smPRL-receptor complex. In addition, they suggest that cooperative interactions may be involved in the binding of smPRL to mouse hepatic receptors.