The binding of human fibrinogen degradation fragments D1, E, X, and Y, as well as fibrin fragment D1 dimer, to mouse peritoneal macrophages was examined. A Scatchard plot of fragment D1 binding was biphasic, suggesting two classes of receptors. Fragments D1, D1 dimer, X, and Y in low concentrations bound to macrophages with high affinity (Kd = 23 to 73 X 10(-11) mol/L). Fragment E bound specifi...

We have examined the affinity shown by the immunoglobulin fraction from each of five sera containing macroamylase for amylases from different sources: human saliva or human, porcine, or ovine pancreas. High affinity constants, 0.4 x 1010 to 7.2 x 1010 LJmol, were found in competitive binding experiments with human or porcine pancreatic amylase. All but one serum yielded linear Scatchard plots, ...

Radiolabeled triiodothyronine (T3) binding to isolated nuclei was measured to compare the binding characteristics of the nuclear receptors in rabbit ventricular and atrial muscle cells. Scatchard analysis of the binding data yielded a maximum binding capacity of 170 +/- 20 fmol per mg DNA and apparent dissociation constant of 525 +/- 100 pM for ventricular nuclei. The binding capacity and the d...

Gonadotropic hormones are required for the induction and maintenance of tumors arising in ovaries that have been transplanted to the spleens of gonadectomized mice. The characteristics of gonadotropin receptors for human chorionic gonadotropin (HCG)-luteinizing hormone on cells from these tumors of varying size, age, and morphology have been determined. The specific binding of 125I-labeled HCG ...

A new method was optimized for rapid screening of 17β-estradiol (E2) in water under 10 min. Molecularly imprinted polymer (MIP) particles (325 ± 25 nm) were added in a water sample at pH 5.5 and 20°C to form a suspension. Fluorescence emission from E2 nonspecifically bound onto the MIP particles was first quenched by large gold nanoparticles (43 ± 5 nm). The Stern-Volmer plot was linear, with d...

ment and increased linearly for 72 h. Receptor expression was dependent on new protein synthesis. At 48 h, Scatchard analysis demonstrated 2.4 X 105 receptors/ cell with a KD of 1.3 nM. In contrast to induction of HL60 differentiation by dimethyl sulfoxide, retinoic acid, or phorbol myristate acetate, the developmental programs initiated by agents that raised intracellular adenosine 3'5'-cyclic...

Neutrophils elicited in the peritoneal cavity of guinea pigs were purified on Percoll gradients and their chemotactic response to hrIL-8 and fMLP measured in vitro. hrIL-8 and fMLP were effective chemoattractants with optimal concentrations of 6 x 10(-9) and 1 x 10(-7) M, respectively. Scatchard analysis revealed approximately 205,000 IL-8 receptors/cell and 34,000 fMLP receptors/cell with KD v...

largely freed of the protein activator, possess low enzyme activity which is independent of Ca”+. Addition of excess protein activator stimulates the enzyme activity 6to lofold. This activation by the protein activator is shown to be completely dependent on the presence of low concentrations of Ca2+. The concentration of Ca?+ required to give 50% of the maximal activation is 2.3 NM. An equilibr...

The interaction of Methylene Blue (MB) with chondroitin-4-sulfate (CHS) has been investigated using spectroscopic techniques, including UV-Vis absorption, Rayleigh resonance scattering (RRS), and circular dichroism (CD). The addition of CHS caused a decrease in the absorbance of MB at 664 nm with a new absorption band appearing at 570 nm, enhanced RRS at 314 nm and 560 nm, and also resulted in ...

Biologically active phorbol ester derivatives displace [3H]phorbol-12, 13-dibutyrate from thioglycollate-elicited mouse peritoneal macrophages in a time-, temperature-, and concentration-dependent manner. Scatchard analysis revealed an apparent Kd of 54.1 nM and 8.0 X 10(5) sites/cell, indicating that these macrophages possess saturable, high-affinity phorbol ester-binding sites. These derivati...