Reaction of (/sup 3/H)-taurine maleimide with platelet surface thiols
Taurine Maleimide (2-maleimidoethanesulfonate, TM) was synthesized from (2-/sup 3/H)-taurine and methoxycarbonylmaleimide (MCM). The yield of a 1 ..mu..mol synthesis approached 100% (based on taurine) when MCM was used in 4-fold excess. The product (TM*) was purified by ion exchange chromatography. TM* reacted irreversibly with thiol groups on the surface of washed human platelets, leading to incorporation of radioactivity into platelet pellets. Incorporation was blocked by cysteine, mercuribenzenesulfonate (MBS), dithiobisnitrobenzoate, and N-ethylmaleimide, but not by taurine or by inhibitors of anion transport. Reaction of TM* with platelets showed the dependence on time and concentration characteristics of a bimolecular reaction. The number of reactive sites ranged from 1 to 5 x 10/sup 5//platelet, and the apparent rate constant from 1 to 3 x 10/sup 3//(M x min). TM was less effective than MBS as an inhibitor of platelet aggregation induced by several agents. TM had no effect on the uptake of serotonin, taurine, or phosphate by the platelets, processes which are sensitive to MBS. These differences, considered with the similarity in size and charge of TM and MBS, suggest that classes of thiols defined as exofacial by their accessibility to MBS can differ substantially in their reactivity with other impermeant reagents.
- Research Organization:
- Temple Univ., Philadelphia, PA
- OSTI ID:
- 6904981
- Report Number(s):
- CONF-8606151-; TRN: 87-004074
- Journal Information:
- Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Vol. 45:6; Conference: 76. annual meeting of the Federation of American Society for Experimental Biology, Washington, DC, USA, 8 Jun 1986
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
59 BASIC BIOLOGICAL SCIENCES
BLOOD PLATELETS
BLOOD COAGULATION
IMIDES
BIOCHEMICAL REACTION KINETICS
THIOLS
ION EXCHANGE CHROMATOGRAPHY
TAURINE
TRACER TECHNIQUES
TRITIUM COMPOUNDS
AMINES
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BODY FLUIDS
CHROMATOGRAPHY
ISOTOPE APPLICATIONS
KINETICS
LABELLED COMPOUNDS
MATERIALS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC SULFUR COMPOUNDS
REACTION KINETICS
SEPARATION PROCESSES
SULFONIC ACIDS
560300* - Chemicals Metabolism & Toxicology
550201 - Biochemistry- Tracer Techniques