LACTOFERRIN - ITS ROLE AS A GA-67-BINDING PROTEIN IN POLYMORPHONUCLEAR LEUKOCYTES

  • 1 January 1981
    • journal article
    • research article
    • Vol. 22  (1) , 32-37
Abstract
Gallium-67 bound to lactoferrin-an Fe-binding protein found in high concentration in [human] polymorphonuclear leukocytes(PMN)-was isolated from PMN that had previously been incubated with Ga-67 citrate. Although the cell-labeling efficiency was highly variable (0.026-10%), much of the activity that did bind to the PNMs (74.8 .+-. 10%) was recovered in the supernatant after sonication and centrifugation. About half (.apprx. 47%) of the PMN-bound activity was retained after dialysis and was presumably bound to macromolecules in the supernatant. When this retained activity was placed on a column containing immobilized antilactoferrin antibody, almost 3/4 of the activity was bound to the column. This bound activity was 36 .+-. 17% of the total activity absorbed by the PMN. The addition to the antilactoferrin column of a known antigen-antibody-dissociating agent caused the dissolution of the complex. No significant activity was bound to a control column. Lactoferrin is evidently a major Ga-67-binding protein present in PMN and it may play a major role in Ga-67 localization in an abscess. The contention that molecules binding ferric iron have an important effect on Ga-67 distribution in vivo is supported.