| Autor: |
Paus, Elisabeth, Myklebust, Arne T. |
| Zdroj: |
Tumor Biology (Springer Science & Business Media B.V.); 1996, Vol. 17 Issue 5, p271-280, 10p |
| Abstrakt: |
The isoforms of γ-enolase were characterized in serum from patients with small-cell lung cancer (SCLC) and in extracts from SCLC cell lines and malignant melanoma tumor tissue. Large variations in the expression of the 3 γ-isoforms of enolase were observed. These forms probably represent the ho-modimeric γγ-enolase, the heterodimeric αγ-enolase and the monomeric forms of γ-enolase. Only the dimeric forms are enzymatically active. The predominant γ-enolase in the cell lines is the heterodimeric αγ-enolase. The SCLC cell lines can be divided into two groups: one with negligible γγ-enolase expression and considerable amounts of the nonneuronal αα-enolase and a second group with a large fraction of γγ-enolase concomitant with a low expression of α-enolase. Similar patterns are observed in tissue extracts from malignant melanoma. When changing buffer conditions by increasing the ionic strength and decreasing the Mg2+ concentration, interconver-sions between the isozymes occur. In contrast to the predominant αγ-enolase in extracts from cell lines, the multiple forms of γ-enolase in serum might be caused by a subunit exchange facilitated by the low Mg2+ concentration in plasma. However, there seems to be a stable equilibrium between the isoforms in undiluted patient serum. The induction of subunit exchange by perturbation in ionic strength and/or Mg2+ concentration indicates a need for caution when choosing diluents for use in assays for neuron-specific enolase. Copyright © 1996 S. Karger AG, Basel [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
|
