Structural features in carrageenan that interact with a heparin- binding hematopoietic growth factor and modulate its biological activity

The effects of carrageenans' structural features on its interaction with granulocyte colony-stimulating factor (G-CSF) and on the growth and differentiation of a G-CSF dependent leukemia cell line (NFS-60) were studied. X, L, and K carrageenans, with decreasing contents of sulfation, bound to G-CSF with binding constants of (6.2 +/- 0.6) x 10(5) M-1, (7.4 +/- 0.5) x 10(5) M-1 and (6.0 +/- 0.4) x 10(5) M-1, and with 27.7 +/- 0.2, 17.4 +/- 0.1 and 8.4 +/- 0.1 binding sites, respectively. However, K carrageenan oligosaccharide had no affinity for G-CSF. The three carrageenans significantly inhibited G-CSF-induced growth of NFS-60 cells. The high sulfate content X carrageenan could also induce the maturation of the cells, but relatively low sulfate content L and K carrageenans could not. The results suggested that G-CSF-carrageenan bindings were dependent on carrageenans' sulfate contents and chain lengths, which could also affect the growth and differentiation of NFS-60 cells. (c) 2006 Elsevier B.V. All rights reserved.