Forgot your Password

If you have forgotten your password, please enter your account email below and we will reset your password and email you the new password.


Login to SciCrunch


Register an Account

Delete Saved Search

Are you sure you want to delete this saved search?


NIF LinkOut Portal


Characterization of semenogelin II and its molecular interaction with prostate-specific antigen and protein C inhibitor.

Kise H, Nishioka J, Kawamura J, Suzuki K
European journal of biochemistry / FEBS


The serine protease, prostate-specific antigen (PSA), its protein substrates, semenogelin (Sg) I and II, and protein C inhibitor (PCI) have been described as components of human seminal plasma. PCI was found to inhibit the PSA-catalyzed degradation of insoluble coagula Sg I + II by forming a PSA-PCI complex. Digestion of seminal coagula with PSA released PCI and PSA-PCI complex from the coagula into a soluble phase, suggesting the presence of active PCI binding to the coagula. To investigate the molecular interaction of Sg with PSA and PCI, we purified Sg II from seminal coagula as a soluble form and found that Sg II is glycosylated with heterogeneous carbohydrate moieties. Sg II bound to the solid-phase complex of diisopropylfluorophosphate (iPr2FP) and PSA with an apparent dissociation constant (kd) of 41 nM and to PCI with a Kd of 28 nM. The binding of Sg II to iPr2P-PSA was not affected by PCI and that of Sg II to PCI was not affected by iPr2P-PSA, suggesting that Sg II forms a ternary complex with PSA and PCI. The bindings of Sg II to both iPr2P-PSA and PCI were influenced by pH, ionic strength, heparin, dextran sulfate, and divalent cations, particularly by Zn2+. Treatment of Sg II with heparinase, heparitinase, N-glycanase, or with O-glycanase following sialidase did not affect the binding of Sg II to iPr2P-PSA and PCI. These findings suggested that PCI bound to Sg in seminal vesicles regulates the PSA-catalyzed degradation of Sg in seminal plasma, and that the binding of PCI and PSA to Sg is modulated by several factors such as pH, ionic strength, divalent cations, and heparin-like substances in seminal plasma.

  1. Welcome

    Welcome to NIF. Explore available research resources: data, tools and materials, from across the web

  2. Community Resources

    Search for resources specially selected for NIF community

  3. More Resources

    Search across hundreds of additional biomedical databases

  4. Literature

    Search Pub Med abstracts and full text from PubMed Central

  5. Insert your Query

    Enter your search terms here and hit return. Search results for the selected tab will be returned.

  6. Join the Community

    Click here to login or register and join this community.

  7. Categories

    Narrow your search by selecting a category. For additional help in searching, view our tutorials.

  8. Query Info

    Displays the total number of search results. Provides additional information on search terms, e.g., automated query expansions, and any included categories or facets. Expansions, filters and facets can be removed by clicking on the X. Clicking on the + restores them.

  9. Search Results

    Displays individual records and a brief description. Click on the icons below each record to explore additional display options.