Neuroscience 2003 Abstract
| Presentation Number: | 470.8 |
|---|---|
| Abstract Title: | Synthesis and characterization of a gadolinium-labeled CRF analog for magnetic resonance imaging. |
| Authors: |
Jahn, O.*1
; Zhang, H.2
; Sasse, A.1
; Tezval, H.1
; van Werven, L.1
; Eckart, K.1
; Wyrwicz, A.2
; Spiess, J.1
1Dept. of Mol. NeuroEndrocrinol., Max Planck Inst. for Exptl. Med., Goettingen, Germany 2IL, Hermann Rein Strasse 3, 37075, |
| Primary Theme and Topics |
Synaptic Transmission and Excitability - G-Protein linked Receptors -- Peptide receptors |
| Secondary Theme and Topics | Synaptic Transmission and Excitability<br />- Neurotransmitters<br />-- Peptides |
| Session: |
470. Peptide Receptors II Poster |
| Presentation Time: | Monday, November 10, 2003 4:00 PM-5:00 PM |
| Location: | Morial Convention Center - Hall F-I, Board # D25 |
| Keywords: | CRF receptor, CRF binding protein, MRI |
Corticotropin-releasing factor (CRF) is a neuromodulator of brain functions such as learning and anxiety, and is involved in several psychiatric disorders. Targeting CRF binding sites with spatial and temporal resolution by using magnetic resonance imaging (MRI) would greatly facilitate research on the CRF system. Therefore, we synthesized and pharmacologically characterized a CRF analog labeled with gadolinium, the contrast agent most commonly used in MRI.
The chelator DOTA was coupled to the N-terminus of human/rat CRF (h/rCRF) under standard solid phase peptide synthesis conditions. The obtained DOTA-h/rCRF was purified and loaded with gadolinium (Gd) in a reaction monitored with mass spectrometry. After purification, Gd-DOTA-h/rCRF was tested for its pharmacological properties using transfected human embryonic kidney (HEK) 293 cells producing either rat CRF receptor (CRFR) 1, mouse CRFR2β or rat CRF binding protein (CRFBP). The affinities of Gd-DOTA-h/rCRF to rat CRFR1 (IC50 = 4.5 nM) and mouse CRFR2β (IC50 = 120 nM) were only slightly decreased by a factor of three compared to those of the parent peptide h/rCRF. Identical subnanomolar affinities of Gd-DOTA-h/rCRF and h/rCRF were determined for binding to rat CRFBP. Thus, N-terminal modification of h/rCRF with the chelator did not alter the binding profile of this peptide. We are now determining the MR imaging characteristics of Gd-DOTA-h/rCRF interacting with CRFBP in solution and CRF receptor produced by cell lines. It is anticipated that Gd-DOTA-h/rCRF or related analogs will be valuable tools for targeting CRF binding sites in vitro and in vivo.
The chelator DOTA was coupled to the N-terminus of human/rat CRF (h/rCRF) under standard solid phase peptide synthesis conditions. The obtained DOTA-h/rCRF was purified and loaded with gadolinium (Gd) in a reaction monitored with mass spectrometry. After purification, Gd-DOTA-h/rCRF was tested for its pharmacological properties using transfected human embryonic kidney (HEK) 293 cells producing either rat CRF receptor (CRFR) 1, mouse CRFR2β or rat CRF binding protein (CRFBP). The affinities of Gd-DOTA-h/rCRF to rat CRFR1 (IC50 = 4.5 nM) and mouse CRFR2β (IC50 = 120 nM) were only slightly decreased by a factor of three compared to those of the parent peptide h/rCRF. Identical subnanomolar affinities of Gd-DOTA-h/rCRF and h/rCRF were determined for binding to rat CRFBP. Thus, N-terminal modification of h/rCRF with the chelator did not alter the binding profile of this peptide. We are now determining the MR imaging characteristics of Gd-DOTA-h/rCRF interacting with CRFBP in solution and CRF receptor produced by cell lines. It is anticipated that Gd-DOTA-h/rCRF or related analogs will be valuable tools for targeting CRF binding sites in vitro and in vivo.
Supported by <i>Max Planck Society and NIH grant R01 MH58912</i>
Sample Citation:
[Authors]. [Abstract Title]. Program No. XXX.XX. 2003 Neuroscience Meeting Planner. New Orleans, LA: Society for Neuroscience, 2003. Online.
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