Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: EC:3.4.24.27 (
thermolysin
)
1,894
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
P-selectin on platelets and endothelial cells and
E-selectin
on endothelial cells are leukocyte receptors that recognize lineage-specific carbohydrates on neutrophils and monocytes. The proposed ligands for these receptors contain the Le(x) core and sialic acid. Since other investigators have shown that both
E-selectin
and P-selectin bind to sialylated Le(x), we evaluated whether
E-selectin
and P-selectin recognize the same counter-receptor on leukocytes. The interaction of HL60 cells with Chinese hamster ovary (CHO) cells expressing P-selectin or
E-selectin
was studied. To determine whether a protein component is required in addition to sialyl Le(x) for either P-selectin or
E-selectin
recognition, HL60 cells or neutrophils were digested with proteases, including chymotrypsin, elastase, proteinase Glu-C, ficin, papain, or
thermolysin
. Cells treated with these proteases bound
E-selectin
but not P-selectin. Fucosidase or neuraminidase treatment of HL60 cells markedly decreased binding to both
E-selectin
- and P-selectin-expressing CHO cells. Growth of HL60 cells in tunicamycin inhibited the ability of these cells to support P-selectin-mediated binding and, to a lesser extent,
E-selectin
-mediated binding. Purified P-selectin inhibited CHO:P-selectin binding to HL60 cells, but incompletely inhibited CHO:
E-selectin
binding to HL60 cells. However, purified soluble
E-selectin
inhibited CHO:P-selectin and CHO:
E-selectin
binding to HL60 cells equivalently and completely. COS cells, unable to bind to
E-selectin
or P-selectin, bound
E-selectin
but not P-selectin upon transfection with alpha-1,3-fucosyltransferase or alpha-1,3/1,4-fucosyltransferase. Similarly, LEC 11 cells expressing sialyl Le(x) bound
E-selectin
- but not P-selectin-expressing CHO cells. Sambucus nigra lectin, specific for the sialyl-2,6 beta Gal/GalNAc linkage, inhibited P-selectin but not
E-selectin
binding to HL60 cells. Although sialic acid and Le(x) are components of the P-selectin ligand and the
E-selectin
ligand, these results indicate that the ligands are related, having overlapping specificities, but are structurally distinct. A protein component containing sialyl Le(x) in proximity to sialyl-2,6 beta Gal structures on the P-selectin ligand may contribute to its specificity for P-selectin.
...
PMID:P-selectin and E-selectin. Distinct but overlapping leukocyte ligand specificities. 137 36
