ADAM 12-S cleaves IGFBP-3 and IGFBP-5 and is inhibited by TIMP-3.
ADAMs are a family of multidomain proteins having proteolytic and cell adhesion activities. We have previously shown that ADAM 12-S, the secreted soluble form of human ADAM 12, is a catalytically active protease. We now describe the purification of full-length recombinant ADAM 12-S and demonstrate that it cleaves insulin-like growth factor binding protein-3 (IGFBP-3). This result supports a role for ADAM 12-S in the degradation of IGFBP-3 in the blood of pregnant women. Furthermore, we tested for proteolysis of other members of the IGF binding protein family and found that ADAM 12-S cleaves IGFBP-5 in addition to IGFBP-3, but does not cleave IGFBP-1, -2, -4, or -6. ADAM 12-S may therefore be the IGFBP-5 protease that is secreted by osteoblasts and other cells. Cleavage of both IGFBP-3 and -5 by ADAM 12-S was inhibited by TIMP-3, raising the possibility that TIMP-3 is a physiological inhibitor of ADAM 12-S.
Loechel
F
F
Institute of Molecular Pathology, University of Copenhagen, Frederik V's Vej 11, Copenhagen, DK-2100, Denmark.
Fox
J W
JW
Murphy
G
G
Albrechtsen
R
R
Wewer
U M
UM
D051722:ADAM Proteins; D000072199:ADAM12 Protein; D000595:Amino Acid Sequence; D019483:Disintegrins / Q000378:metabolism; D005260:Female; D006801:Humans; D018970:Insulin-Like Growth Factor Binding Protein 1 / Q000378:metabolism; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000378:metabolism*; D018975:Insulin-Like Growth Factor Binding Protein 5 / Q000378:metabolism*; D008565:Membrane Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D008666:Metalloendopeptidases / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D010446:Peptide Fragments / Q000737:chemistry; D011247:Pregnancy; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D013379:Substrate Specificity; D019717:Tissue Inhibitor of Metalloproteinase-3 / Q000494:pharmacology*
D019483:Disintegrins; D018970:Insulin-Like Growth Factor Binding Protein 1; D018972:Insulin-Like Growth Factor Binding Protein 3; D018975:Insulin-Like Growth Factor Binding Protein 5; D008565:Membrane Proteins; D010446:Peptide Fragments; D011994:Recombinant Proteins; D019717:Tissue Inhibitor of Metalloproteinase-3; D051722:ADAM Proteins; D000072199:ADAM12 Protein; C000606480:ADAM12 protein, human; D008666:Metalloendopeptidases