An examination of the proteolytic activity for bovine pregnancy-associated glycoproteins 2 and 12.
The pregnancy-associated glycoproteins (PAGs) represent a complex group of putative aspartic peptidases expressed exclusively in the placentas of species in the Artiodactyla order. The ruminant PAGs segregate into two classes: the 'ancient' and 'modern' PAGs. Some of the modern PAGs possess alterations in the catalytic center that are predicted to preclude their ability to act as peptidases. The ancient ruminant PAGs in contrast are thought to be peptidases, although no proteolytic activity has been described for these members. The aim of the present study was to investigate (1) if the ancient bovine PAGs (PAG-2 and PAG-12) have proteolytic activity, and (2) if there are any differences in activity between these two closely related members. Recombinant bovine PAG-2 and PAG-12 were expressed in a baculovirus expression system and the purified proteins were analyzed for proteolytic activity against a synthetic fluorescent cathepsin D/E substrate. Both proteins exhibited proteolytic activity with acidic pH optima. The k(cat)/K(m) for bovine PAG-2 was 2.7x10(5) m(-1) s(-1) and for boPAG-12 it was 6.8x10(4) m(-1) s(-1). The enzymes were inhibited by pepstatin A with a K(i) of 0.56 and 7.5 nm for boPAG-2 and boPAG-12, respectively. This is the first report describing proteolytic activity in PAGs from ruminant ungulates.
Telugu
Bhanu Prakash V L
BPVL
Division of Animal Sciences, University of Missouri, 163 ASRC, Columbia, MO 65211, USA.|Current address: Christopher S. Bond Life Sciences Center, University of Missouri, 245 LSC, Columbia, MO 65211, USA.
Palmier
Mark O
MO
Department of Biochemistry, University of Missouri, 117 Schweitzer Hall, Columbia, MO 65211, USA.
Van Doren
Steven R
SR
Department of Biochemistry, University of Missouri, 117 Schweitzer Hall, Columbia, MO 65211, USA.
Green
Jonathan A
JA
Division of Animal Sciences, University of Missouri, 163 ASRC, Columbia, MO 65211, USA.
D000818:Animals; D016282:Aspartic Acid Endopeptidases / Q000032:analysis* / Q000037:antagonists & inhibitors / Q000378:metabolism*; D002417:Cattle; D006023:Glycoproteins / Q000032:analysis / Q000037:antagonists & inhibitors / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D010436:Pepstatins / Q000494:pharmacology; D011257:Pregnancy Proteins / Q000032:analysis / Q000037:antagonists & inhibitors / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D011994:Recombinant Proteins / Q000032:analysis / Q000037:antagonists & inhibitors / Q000378:metabolism; D013329:Structure-Activity Relationship
D006023:Glycoproteins; D010436:Pepstatins; D011257:Pregnancy Proteins; D011994:Recombinant Proteins; D016282:Aspartic Acid Endopeptidases; C095584:pregnancy-associated glycoprotein 2; C031375:pepstatin