These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


PUBMED FOR HANDHELDS

Search MEDLINE/PubMed


  • Title: Apolipoprotein(a) kringle 4-containing fragments in human urine. Relationship to plasma levels of lipoprotein(a).
    Author: Mooser V, Seabra MC, Abedin M, Landschulz KT, Marcovina S, Hobbs HH.
    Journal: J Clin Invest; 1996 Feb 01; 97(3):858-64. PubMed ID: 8609245.
    Abstract:
    Apo(a) is a large glycoprotein of unknown function that circulates in plasma as part of lipoprotein(a). Apo(a) is structurally related to plasminogen and contains at least 10 kringle (K)4 repeats (type 1-10), a K5 repeat and sequences similar to the protease domain of plasminogen. Plasminogen generates two biologically active peptides: plasmin and angiostatin, a kringle-containing peptide. As a first step in determining if apo(a) generates a similar kringle-containing peptide, human urine was immunologically examined. Fragments ranging in size from 85 to 215 kD were immunodetected using antibodies directed against epitopes in the K4-type 2 repeat, but not the K4-type 9 repeat or protease domain, NH2-terminal sequence analysis revealed sequences specific for the K4-type 1 repeat, confirming that the fragments are from the NH2 terminus of the K4 array. The amount of urinary apo(a) rose in proportion to the plasma lipoprotein(a) concentration. Even individuals with trace to no apo(a) in plasma had immunodetectable apo(a) fragments in their urine. Intravenous administration of the human urinary apo(a) into mice resulted in the urine. These findings suggest that the apo(a) fragments found in urine are formed extrarenally and then excreted by the kidney.
    [Abstract] [Full Text] [Related] [New Search]