Isolation and biochemical characterization of the soluble and membrane forms of folate binding protein expressed in the ovarian carcinoma cell line IGROV1

FEBS Letters

Facheris, Patrizia²  Tomassetti, Antonella²  Canevari, Silvana²  Colnaghi, Maria I.²  Miotti, Silvia²  Zurawski, Vincent R.²  Coney, Leslie R.¹ 

[1] Cancer Research Division, Centocor, Malvern, PA 19355, USA;Oncologia Sperimentale E, Istituto Nazionale per lo Studio e la Cura del Tumori, via Venezian 1, 20133 Milan, Italy

关键词: Folate binding protein;    Ovarian carcinoma;    Glycosylphosphatidylinositol linkage;    sFBP;    soluble folate binding protein;    mFBP;    membrane folate binding protein;    GPI;    glycosylphosphatidylinositol;    PIPLC;    phospholipase C;    PBS;    phosphate-buffered saline;    DDIRMA;    double-determinant radioimmunoassay;   

DOI  :  10.1016/0014-5793(93)81510-7

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The human ovarian carcinoma cell line, IGROV1, produces two forms of folate binding protein (FBP), the membrane form that is anchored to the cell surface by a glycosylphosphatidylinositol tail and the soluble form that is shed into the tissue culture medium. Both forms are recognized by the monoclonal antibodies MOv18 and MOv19. Here we describe their purification and biochemical characterization. The purified soluble protein appeared as a single band with an apparent M _r of 36 kDa after SDS-PAGE, whereas the membrane form appeared as a single band with an apparent M _r of 38 kDa. The size difference between the two forms of FBP was confirmed by gel filtration of both the native and the N-glycanase-treated proteins. Both purified proteins had equal capacity to bind folic acid. The immunological cross-reactivity and the folic acid binding capability of the FBPs extracted from IGROV1 gave more evidence of the possible existence of a precursor-product relationship between them.

【 授权许可】

Unknown