ADAMTS-4 (aggrecanase-1): N-terminal activation mechanisms.
ADAMTS-4 (aggrecanase 1) is synthesized as a latent precursor protein that may require activation through removal of its prodomain before it can exert catalytic activity. We examined various proteinases as well as auto-activation under a wide range of conditions for removal of the prodomain and induction of enzymatic activity. The proprotein convertases, furin, PACE4, and PC5/6 efficiently removed the prodomain through cleavage at Arg(212)/Phe(213), generating an active enzyme. Of a broad range of proteases evaluated, only MMP-9 and trypsin were capable of removing the prodomain. In the presence of mercuric compounds, removal of the prodomain through autocatalysis was not observed, nor was it observed at temperatures from 22 to 65 degrees C, at ionic strengths from 0.1 to 1M, or at acidic/neutral pH. At basic pH 8-10, removal of the prodomain by autocatalysis occurred, generating an active enzyme. In conclusion, the pro-form of ADAMTS-4 is not catalytically active and only a limited number of mechanisms mediate its N-terminal activation.
Tortorella
Micky D
MD
Pfizer Global Research and Development, 700 Chesterfield Parkway, Chesterfield, MO 60013, USA. micky.d.tortorella@pfizer.com
Arner
Elizabeth C
EC
Hills
Robert
R
Gormley
Jennifer
J
Fok
Kam
K
Pegg
Lyle
L
Munie
Grace
G
Malfait
Anne-Marie
AM
D051722:ADAM Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry*; D000071121:ADAMTS4 Protein; D000595:Amino Acid Sequence; D000818:Animals; D019483:Disintegrins / Q000737:chemistry*; D004789:Enzyme Activation; D006801:Humans; D006863:Hydrogen-Ion Concentration; D045726:Metalloproteases / Q000737:chemistry*; D008969:Molecular Sequence Data; D009994:Osmolar Concentration; D010663:Phenylmercury Compounds / Q000737:chemistry; D011348:Procollagen N-Endopeptidase / Q000037:antagonists & inhibitors / Q000737:chemistry*; D043484:Proprotein Convertases / Q000737:chemistry*; D011994:Recombinant Proteins / Q000737:chemistry; D012697:Serine Endopeptidases / Q000737:chemistry*; D013696:Temperature
D019483:Disintegrins; D010663:Phenylmercury Compounds; D011994:Recombinant Proteins; D045726:Metalloproteases; D043484:Proprotein Convertases; D012697:Serine Endopeptidases; D051722:ADAM Proteins; D011348:Procollagen N-Endopeptidase; D000071121:ADAMTS4 Protein; C000603918:ADAMTS4 protein, human