Photoaffinity studies of the tubulin-colchicine binding site

Thesis/Dissertation · Thu Jan 01 04:00:00 EST 1987

OSTI ID:6902292

Hahn, K M

A variety of colchicine derivatives were synthesized and coupled with 3,3,3-trifluoro-2-diazapropionyl chloride (TFDP-Cl) to produce colchicine photoaffinity analogs for use in tubulin labelling studies. Photoaffinity analogs of allocolchicine and podophylotoxin were also made using the same photoreactive moiety. Several labels were found to be effective inhibitors of tubulin polymerization. The approximate tubulin binding constants of the labels, calculated from polymerization inhibition data, varied between 2.2 x 10/sup 5/ to 2.5 x 10/sup 3/ M/sup -1/. The labels chosen for use in tubulin labelling experiments were (N-TFDP) deacetyl-thiocolchicine 1, (O-TFDP)thiocolchifoline 2, and (O-TFDP)-2-demethylthiocolchicine 3. Compound 1 was found to bind tubulin reversibly and to competitively inhibit colchicine binding. Methods for the incorporation of tritium and /sup 14/C in these labels were developed. Conditions were found which caused labels to insert into solvent without photorearrangement of the colchicine skeleton. Catalytic base caused the ..cap alpha..-diazo amide of 1 to rearrange to a triazole.

• Research Organization: Virginia Univ., Charlottesville (USA)
• OSTI ID: 6902292
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALKALOIDS
ANTIMITOTIC DRUGS
ANTIPYRETICS
BIOCHEMICAL REACTION KINETICS
CARBON 14 COMPOUNDS
CENTRAL NERVOUS SYSTEM DEPRESSANTS
CHEMICAL REACTIONS
COLCHICINE
DRUGS
ISOTOPE APPLICATIONS
KINETICS
LABELLED COMPOUNDS
LABELLING
MEMBRANE PROTEINS
ORGANIC COMPOUNDS
POLYMERIZATION
PROTEINS
REACTION KINETICS
RECEPTORS
TRACER TECHNIQUES
TRITIUM COMPOUNDS