Aqueous solubility of beryllium(II) at physiological pH: effects of buffer composition and counterions.
Prep Biochem Biotechnol
; 50(6): 585-591, 2020.
Article
in En
| MEDLINE
| ID: mdl-31990243
ABSTRACT
Beryllium ion elicits p53-mediated cell cycle arrest in some types of human cancer cells, and it is a potent inhibitor of GSK3 kinase activity. Paradoxically, Be2+ is regarded to have almost negligible aqueous solubility at physiological pH, due to precipitation as Be(OH)2. This study demonstrates that the interaction of Be2+ with serum proteins greatly increases its effective solubility. In typical serum-supplemented mammalian cell culture medium, Be2+ was soluble up to about 0.5 mM, which greatly exceeds the concentration needed for biological activity. Some biochemical studies require protein-free Be2+ solutions. In such cases, the inclusion of a specific inorganic counterion, sulfate, increased solubility considerably. The role of sulfate as a solubility-enhancing factor became evident during preparation of buffered solutions, as the apparent solubility of Be2+ depended on whether H2SO4 or a different strong acid was used for pH adjustment. The binding behavior of Be2+ observed via isothermal titration calorimetry was affected by the inclusion of sodium sulfate. The data reflect a "Diverse Ion Effect" consistent with ion pair formation between solvated Be2+ and sulfate. These insights into the solubility behavior of Be2+ at physiological and near-physiological pH will provide guidance to assist sample preparation for biochemical studies.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Beryllium
/
Water
/
Blood Proteins
Limits:
Humans
Language:
En
Journal:
Prep Biochem Biotechnol
Year:
2020
Document type:
Article