Involvement of disulfide bond formation in the activation of heparanase.
Heparanase is overexpressed in many solid tumor cells and is capable of specifically cleaving heparan sulfate, and this activity is associated with the metastatic potential of tumor cells; however, the activation mechanism of heparanase has remained unknown. In this study, we investigated the link between disulfide bond formation and the activation of heparanase in human tumor cells. Mass spectrometry analysis of heparanase purified from a conditioned medium of human fibrosarcoma cells revealed two disulfide bonds, Cys127-Cys179 and Cys437-Cys542, and one S-cysteinylation at the Cys211 residue. It was shown that, although the formation of the Cys127-Cys179 bond and S-cysteinylation at Cys211 have little effect on heparanase function, the disulfide bond between Cys437 and Cys542 is necessary for the secretion and activation of heparanase. Thus, the present findings will provide a basis for the further refinement of heparanase structural studies and for the development of novel heparanase inhibitors.
Simizu
Siro
S
Antibiotics Laboratory, Discovery Research Institute, RIKEN, Saitama, Japan.
Suzuki
Takehiro
T
Muroi
Makoto
M
Lai
Ngit Shin
NS
Takagi
Satoshi
S
Dohmae
Naoshi
N
Osada
Hiroyuki
H
D000595:Amino Acid Sequence; D045744:Cell Line, Tumor; D003545:Cysteine / Q000737:chemistry / Q000378:metabolism; D004220:Disulfides / Q000737:chemistry / Q000378:metabolism; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000494:pharmacology; D005354:Fibrosarcoma / Q000201:enzymology / Q000235:genetics; D005966:Glucuronidase / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008969:Molecular Sequence Data; D013329:Structure-Activity Relationship; D014162:Transfection; D000099175:Heparanase
D003545:Cysteine; D004220:Disulfides; D004791:Enzyme Inhibitors; D005966:Glucuronidase; D000099175:Heparanase