Identification and activation of profollipsin, a latent precursor form of porcine follipsin.
A latent protease has been identified in column fractions obtained during the purification of the porcine ovarian serine protease follipsin. The latent enzyme was readily activated by trypsin treatment. The trypsin-activated enzyme was purified using a benzamidine-Sepharose 6B column and was shown to be composed of two distinct, covalently associated polypeptides with Mr of 45000 and 32000. This polypeptide chain composition, together with its substrate specificity, inhibition profile using various protease inhibitors, cross-reactivity with anti-follipsin antibody, and ability to activate single-chain precursor tissue plasminogen activator, indicated its identity as porcine follipsin. The activation of the enzyme with trypsin was found to occur by the hydrolysis of an internal peptide bond resulting in a two-chain structure. Thus, we conclude that the latent enzyme is the inactive precursor form (profollipsin) of follipsin. The present study also shows that the follicular fluid of porcine ovary contains a profollipsin-activating enzyme activity.
Kihara
T
T
Division of Biological Sciences, Graduate School of Science, Hokkaido University, Sapporo, Japan.
Ohnishi
J
J
Kohyama
K
K
Moriyama
A
A
Takahashi
T
T
D000818:Animals; D003429:Cross Reactions; D004789:Enzyme Activation; D004792:Enzyme Precursors / Q000737:chemistry* / Q000276:immunology / Q000378:metabolism; D005260:Female; D005343:Fibrinolytic Agents / Q000378:metabolism; D015571:Follicular Fluid / Q000378:metabolism; D008970:Molecular Weight; D011994:Recombinant Proteins / Q000378:metabolism; D012697:Serine Endopeptidases / Q000737:chemistry* / Q000276:immunology / Q000378:metabolism*; D013379:Substrate Specificity; D013552:Swine; D010959:Tissue Plasminogen Activator / Q000378:metabolism; D014357:Trypsin / Q000378:metabolism; D014568:Urokinase-Type Plasminogen Activator / Q000378:metabolism
D004792:Enzyme Precursors; D005343:Fibrinolytic Agents; D011994:Recombinant Proteins; D012697:Serine Endopeptidases; C088241:follipsin; D014357:Trypsin; D010959:Tissue Plasminogen Activator; D014568:Urokinase-Type Plasminogen Activator; C106362:profollipsin; C067551:saruplase