Abstract
A GTP photoaffinity probe (125I-APTG) was developed that incorporated an [125I]-N-(4-azidophenyl)-2-amino-3-(4-hydroxy-3-iodophenyl)propionamide group at the ?-position of GTP through a phos-phonamide linkage. A combination of saturation and GTP protection studies (90% protection at 25 µM GTP with an apparent of 5 µM) validated the use of this new probe as a satisfactory GTP mimic. This probe offered the advantage of possessing an 125I radiolabel external to the GTP moiety, in contrast to the previously reported [?32P]-8-N3GTP that possessed an internal 32P radiolabel. This novel feature accommodated the purification of photolabeled peptides using a combination of ion-exclusion, gel filtration, and HPLC techniques. [125I]APTG was used to identify a peptide (ݺ65-79) in the exchangeable GTP-binding domain of the ݭsubunit of tubulin.
Original language | English |
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Pages (from-to) | 337-344 |
Number of pages | 8 |
Journal | Bioconjugate Chemistry |
Volume | 1 |
Issue number | 5 |
DOIs | |
State | Published - Sep 1 1990 |
ASJC Scopus subject areas
- Biotechnology
- Bioengineering
- Biomedical Engineering
- Pharmacology
- Pharmaceutical Science
- Organic Chemistry