Determination of metal-metal distances in E. coli glutamine synthetase by EPR. |
| |
Authors: | J J Villafranca M S Balakrishnan F C Wedler |
| |
Institution: | 1. Departments of Chemistry The Pennsylvania State University University Park, Pennsylvania 16802 USA;2. Renssalaer Polytechnic Institute Troy, New York 12181 USA |
| |
Abstract: | This paper reports the first determination of the distance between the two metal ions (per subunit) of glutamine synthetase. When Mn(II) is bound at the n1 metal ion site its EPR spectrum is diminished in intensity but not broadened as Cr(III)-ATP or Cr(III)-ADP is bound to the enzyme. A paramagnetic spin-spin interaction is responsible for this phenomenon and a metal-metal distance of ~7 Å is calculated for enzyme - Mn(II) - Cr(III)-ATP and ~6Å for enzyme - Mn(II) - Cr(III)-ADP. The metal-metal distance changes slightly when substrates or inhibitors are also bound to the enzyme demonstrating induced conformational changes in the protein at the metal ion sites. |
| |
Keywords: | To whom to address inquiry |
本文献已被 ScienceDirect 等数据库收录! |