Dynamic Light Scattering Studies on Hydrodynamic Properties of Fibrinogen-Fibronectin Complex

Abstract

A high molecular weight 'cryogel' was obtained as insoluble complexes by cold incubation at near-freezing temperatures from heparinized plasma of patients with rheumatoid arthritis. After the cryogel was solubilized at 37 degrees C, 1:1 complex of fibrinogen and fibronectin was purified at room temperature by affinity chromatography on a gelatin-Sepharose 4B. Hydrodynamic properties of the complex were investigated as a function of temperature and NaCl concentration using a dynamic light scattering. The diffusion coefficients of the complex at 20 degrees C decreased with increasing of NaCl concentration as free fibronectin. The complex appears to be a more compact form at low ionic concentration, which is associated with conformational changes of fibronectin. The diffusion coefficient of the complex at 20 degrees C in 0.05 M TrisHCl(pII7.4) containing 0.5 M NaCl was estimated as 8.5 x 10(-8) cm2s-1. The complex did not dissociate over the temperature range from 20 to 37 degrees C. The diffusion coefficients of the complex decreased significantly at 12 degrees C and 40 degrees C. The thermal denaturation of fibrinogen molecule in the complex was observed at 40 degrees C. The CONTIN analysis of the light scattering data showed that the complex associated to form higher aggregates at 15 degrees C, but not at near-freezing temperature. The equilibrium between the complex and higher aggregates appeared reversible.

A Model Incorporating Some of the Mechanical and Biochemical Factors Underlying Clot Formation and Dissolution in Flowing Blood

“…10 5 Daltons) also. As evidence that such an assumption will not yield diffusion coefficients that are much different from the actual value, we point to the data in Le and Dejardin (1998) (data for diffusion coefficient on kininogen in a kininogen-fibrinogen solution in a Tris buffer) and (Nagamatsu et al, 1992, data for diffusion coefficient of fibrinogen -fibronectin complex at dissociation at 378C in a Tris buffer). The diffusion coefficients reported in these studies are of the same order of magnitude as that predicted by the correlation in the appropriate solvents.…”

miR-33a expression sensitizes Lgr5+ HCC-CSCs to doxorubicin via ABCA1

“…We preliminary revealed that Lgr5 + HCC cells were a subset of previously unrecognized tumor cells that displayed the properties of HCC-CSCs. Given that Lgr5 + tumor cells are crucial for the development and progression of colorectal cancer [23][24][25], we reasonably deduce that Lgr5 + HCC-CSCs may be important for the pathogenesis and drug resistance of HCC. However, the exact function, mechanisms, and the prognosis value of Lgr5 in HCC need further study.…”