| 1. |
- Margittai, M., et al.
(author)
-
Single-molecule fluorescence resonance energy transfer reveals a dynamic equilibrium between closed and open conformations of syntaxin 1
- 2003
-
In: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 100:26, s. 15516-15521
-
Journal article (peer-reviewed)abstract
- Protein conformational transitions form the molecular basis of many cellular processes, such as signal transduction and membrane traffic. However, in many cases, little is known about their structural dynamics. Here we have used dynamic single-molecule fluorescence to study at high time resolution, conformational transitions of syntaxin 1, a soluble N-ethylmaleimide-sensitive factor attachment protein receptors protein essential for exocytotic membrane fusion. Sets of syntaxin double mutants were randomly labeled with a mix of donor and acceptor dye and their fluorescence resonance energy transfer was measured. For each set, all fluorescence information was recorded simultaneously with high time resolution, providing detailed information on distances and dynamics that were used to create structural models. We found that free syntaxin switches between an inactive closed and an active open configuration with a relaxation time of 0.8 ms, explaining why regulatory proteins are needed to arrest the protein in one conformational state.
|
|
| 2. |
|
|
| 3. |
- Standal, T, et al.
(author)
-
Serum insulinlike growth factor is not elevated in patients with multiple myeloma but is still a prognostic factor
- 2002
-
In: Blood. - : American Society of Hematology. - 1528-0020 .- 0006-4971. ; 100:12, s. 3925-3929
-
Journal article (peer-reviewed)abstract
- Insulinlike growth factor. 1 (IGF-1) has growth-promoting effects on myeloma cells in vitro as well as in vivo. In this study, we measured the concentration of IGF-1 and its major binding protein, IGF-binding protein 3 (IGFBP-3), in serum from 127 patients with multiple myeloma. Serum had been drawn at the time of diagnosis, before treatment With highdose melphalan. IGFBP-3 in myeloma patients (1.6 +/- 0.73 mug/mL; mean +/- SD) was significantly decreased compared to healthy age- and sex-matched controls (2.2 +/- 0.42 mug/mL). However, IGFBP-3 had no prognostic value in this study. The mean IGF-1 level did not differ between myeloma patients (17.8 +/- 7.7 nM) and controls (17.3 +/- 5.6 nM). Nevertheless, IGF-1 was a strong indicator of prognosis. After 80 months of follow-up, myeloma patients with low levels (< 13 nM) of serum IGF-1 had not reached median survival. In the patient group with IGF-1 levels above 13 nM, median survival was 62 months (P =.006). These findings support the hypothesis of a role for IGF-1 in myeloma disease progression.
|
|
