Structural and functional comparison of the formyl peptide receptor between human leukocytes: HL-60 promyelocytic leukemia cells and polymorphonuclear leukocytes

Thesis/Dissertation · Sat Jan 01 04:00:00 EST 1983

OSTI ID:5959124

Dougherty, R W

The specific binding of (/sup 3/H)-formylmethionyl-leucyl-phenylalanine ((/sup 3/H)fMLP) was evaluated in DMSO (+/- dexamethsone)-stimulated HL-60 promyelocytic leukemia cells and in freshly isolated polymorphonuclear leukocytes (PMN) using standard equilibrium and non-equilibrium binding techniques. At 0/sup 0/, specific binding in both cell systems was saturable with respect to both time and concentration of peptide and was completely reversible. Scatchard analyses of the data suggested a single population of non-interacting binding sites on each cell type. Equilibrium dissociation constants (Kd) for the ligand/receptor interaction determined using three separate binding techniques (i.e., equilibrium, kinetic, and binding competition assays) were very similar within either cell type; however, a small difference was found in binding constants between the two cell types. An essentially exact correlation was found between these peptides affinity for binding in the HL-60 cell and the PMN. A similar high correlation exists between the binding affinity of each peptide and the ability to elicit a biological response - secretion of a granular marker, N-acetylglucosaminidase (NAGA). Maximal hydrolysis of Pl occurred within 10 sec of receptor occupation, the magnitude of which was dependent on the concentration of agonist. The hydrolysis of Pl, but not of PIP/sub 2/, was sensitive to the removal of extracellular Ca/sup + +/ by EGTA. In the HL-60 system, maximal PI hydrolysis preceeded maximal secretion; both of these responses are complete at a time when only 10% of the available receptor population has been occupied.

• Research Organization: Virginia Commonwealth Univ., Richmond (USA)
• OSTI ID: 5959124
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AFFINITY
ALANINES
AMINO ACIDS
BIOCHEMISTRY
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BODY FLUIDS
CARBOXYLIC ACIDS
CHEMICAL BONDS
CHEMISTRY
COMPARATIVE EVALUATIONS
DISEASES
DMSO
HEMIC DISEASES
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LEUKEMIA
LEUKOCYTES
LIGANDS
MATERIALS
NEOPLASMS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
PEPTIDES
PROTEINS
RECEPTORS
SULFOXIDES
TRACER TECHNIQUES
TRITIUM COMPOUNDS