Lysine binding to activated human platelets and its similarity to fibrinogen binding

Galila Agam, Rivka Luria, Orit Shohat, Alexander Dvilansky, Uri Seligsohn, Avinoam Livne

Research output: Contribution to journalArticlepeer-review

2 Scopus citations

Abstract

Platelet surface glycoproteins IIb-IIIa are considered to function as the binding site for fibrinogen. Fibrinogen binding is essential for platelet aggregation and several amines have been shown to inhibit this binding. The present study compares the binding properties of 125I-fibrinogen and [3H]lysine with platelets activated by the Ca2+ ionophore A23187. Many lines of similarities in the binding properties are apparent; however, several differences were also found. The similarities are listed below and the differences are pointed out in parentheses. (a) Marked enhancement by platelet activation; (b) deficiency of binding by thrombasthenic platelets lacking the glycoproteins IIb-IIIa; (c) saturability (fibrinogen binding approaches saturation at more than 12 μM, within 10 min; lysine binding at more than 100 mM within 1 min); (d) Ca2+-dependence (at 1 mM Ca2+ lysine binding is minute and fibrinogen binding is half-saturated); (e) reversibility; the binding achieved within 10 min is exchangeable; dissociation depends upon time and external ligand concentration; (f) inhibition by the oligoamines His-Lys and Lys4; (g) inhibition by serum from a thrombasthenic patient who developed anti-glycoproteins IIb-IIIa antibodies; (h) specificity; alanine neither binds to activated platelets nor inhibits fibrinogen binding; it thus appears that the lysine which associates with activated platelets is mostly bound onto the surface of the cells rather than being incorporated; Moreover, the major site of lysine binding seems to be the complexed glycoproteins IIb-IIIa.

Original languageEnglish
Pages (from-to)293-300
Number of pages8
JournalBiochimica et Biophysica Acta - Molecular Cell Research
Volume847
Issue number3
DOIs
StatePublished - 12 Dec 1985

Keywords

  • (Human platelet)
  • Fibrinogen binding
  • Lysine binding
  • Thrombasthenia

Fingerprint

Dive into the research topics of 'Lysine binding to activated human platelets and its similarity to fibrinogen binding'. Together they form a unique fingerprint.

Cite this