Phenyl azide substituted and benzophenone-substituted phosphonamides of 7-methylguanosine 5 prime -triphosphate as photoaffinity probes for protein synthesis initiation factor eIF-4E and a proteolytic fragment containing the cap-binding site

Journal Article · Tue Jun 12 00:00:00 EDT 1990 · Biochemistry; (United States)

DOI:https://doi.org/10.1021/bi00475a016· OSTI ID:5229493

Chavan, A J; Rychlik, W; Watt, D S; Rhoads, R E ^[1]; Blaas, D; Kuechler, E ^[2]

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1. Univ. of Kentucky, Lexington (USA)
2. Institut fuer Biochemie der Universitaet Wien, Vienna (Austria)

Three photoactive derivatives of the 7-methylguanosine-containing cap of eukaryotic mRNA were used to investigate protein synthesis initiation factor eIF-4E from human erythrocytes and rabbit reticulocytes. Sensitive and specific labeling of eIF-4E was observed with the previously described probe, ({gamma}-{sup 32}P)-{gamma}-(((4-benzoylphenyl)methyl)amido)-7-methyl-GTP. A second probe was synthesized that was an azidophenyltyrosine derivative of m{sup 7}GTP (({sup 125}I)APTM), the monoanhydride of m{sup 7}GDP with ({sup 125}I)-N-(4-azidophenyl)-2-(phosphoramido)-3-(4-hydroxy-3-iodophenyl)propionamide. This probe allowed rapid and quantitative introduction of radioactivity in the last rather than the first step of synthesis and placed the radioactive label on the protein-proximal side of the weak P-N bond. A dissociation constant of 6.9 {mu}M was determined for ({sup 125}I)APTM, which is comparable to the published values for m{sup 7}GTP. A third probe, an azidophenylglycine derivative of m{sup 7}GTP (({sup 32}P)APGM), the monoanhydride of m{sup 7}GDP with ({sup 32}P)-N-(4-azidophenyl)-2-(phosphoramido)acetamide, was also synthesized and shown to label eIF-4E specifically. Unlike ({sup 32}P)BPM and ({sup 125}I)APTM, however, ({sup 32}P)APGM labeled eIF-4E{sup *} approximately 4-fold more readily than intact eIF-4E. Tryptic and CNBr cleavage suggested that eIF-4E{sup *} consists of a protease-resistant core of eIF-4E that retains the cap-binding site and consists of approximately residues 47-182.

• OSTI ID: 5229493
• Journal Information: Biochemistry; (United States), Vol. 29:23; ISSN 0006-2960
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
ENZYME INHIBITORS
CHEMICAL PREPARATION
DERIVATIZATION
TRANSCRIPTION FACTORS
PROTEIN STRUCTURE
AZIDES
BENZOPHENONE
ELECTROPHORESIS
ERYTHROCYTES
GUANOSINE
IODINE 125
MAN
MOLECULAR BIOLOGY
PHOSPHORUS 32
RABBITS
RETICULOCYTES
TYROSINE
AMINO ACIDS
ANIMALS
AROMATICS
AZAARENES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BODY FLUIDS
CARBOXYLIC ACIDS
CHEMICAL REACTIONS
DAYS LIVING RADIOISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
HETEROCYCLIC COMPOUNDS
HYDROXY ACIDS
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
IODINE ISOTOPES
ISOTOPES
KETONES
LIGHT NUCLEI
MAMMALS
MATERIALS
NITROGEN COMPOUNDS
NUCLEI
NUCLEOPROTEINS
NUCLEOSIDES
NUCLEOTIDES
ODD-EVEN NUCLEI
ODD-ODD NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHOSPHORUS ISOTOPES
PRIMATES
PROTEINS
PURINES
RADIOISOTOPES
RIBOSIDES
SYNTHESIS
VERTEBRATES
550201* - Biochemistry- Tracer Techniques