Abstract
Metallothionein, a two-domain protein, naturally binds seven gram atoms of divalent ions such as Zn and Cd. Four of the metals (M1, M5, M6 and M7) are found in the α-domain and three (M2, M3 and M4) in the β-domain. Previous studies have shown that metals in the β-domain are more readily exchangeable, and the level of avidity is site specific. By semi-empirical MNDO modified neglect of diatomic overlap calculations, we found the tendency of binding energy for Cd to be M3 > M2 > M4 in the β-cluster and M5 > M7 > M1, M6 in the α-cluster. Thus, the replacement of Zn by Cd can be expected to follow the order M4 → M2 → M3 in the β-domain and MS → M7 → M1 or M6 in the α-domain. This is reflected by energy differences computed with a series of simulated structures derived from either X-ray crystallography or NMR coordinates.
Original language | English (US) |
---|---|
Pages (from-to) | 1165-1172 |
Number of pages | 8 |
Journal | Protein engineering |
Volume | 9 |
Issue number | 12 |
DOIs | |
State | Published - Dec 1996 |
Externally published | Yes |
Keywords
- Heat of formation
- MNDO
- Metallothionein
- Quantum
- Semi-empirical
ASJC Scopus subject areas
- Biochemistry
- Molecular Biology