| Autor: |
Finn, Bryan E., Kördel, Johan, Thulin, Eva, Sellers, Peter, Forsén, Sture |
| Zdroj: |
FEBS Letters; February 1992, Vol. 298 Issue: 2-3 p211-214, 4p |
| Abstrakt: |
Calbindin D9kis a 75‐residue globular protein made up of two Ca2+‐binding subdomains of the EF‐hand type. In order to examine the subdomains independently, a method was devised to selectively cleave the loop between them. Using site‐directed mutagenesis, a unique methionine was substituted for Pro43in the loop, thus allowing cleavage using cyanogen bromide. Agarose gel electrophoresis shows that the fragments have a high affinity for one another, although less so in the absence of calcium.1H‐NMR spectra of the fragments indicate that the structures of the heterodimers are changed little from that of the intact protein. However, the Ca2+binding constants of the individual subdomains are several orders of magnitude lower than for the corresponding sites in the uncleaved protein. |
| Databáze: |
Supplemental Index |
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