[Localization of the site of human transferrin interacting with cellular receptors using monoclonal antibodies]. / Lokalizatsiia uchastka vzaimodeistviia transferrina cheloveka s kletochnym retseptorom s pomoshchiu monoklonal'nykh antitel.

Antigenic determinants of the human transferrin molecule on the sublobe and lobe levels were localized for 7 monoclonal antibodies. Antibodies used have different effects on the interaction of the transferrin with its receptor. It was concluded that transferrin-receptor recognition was determined by NH2-lobe, the N2-sublobe playing major part. Dimerization of the transferrin molecules in solution was detected. Using the panel of monoclonal antibodies it was shown that dimerization accomplished by means of the COOH-lobes of transferrin molecules, the sites of interaction of the NH2-lobe with receptor being exposed. A model of the transferrin - receptor complex is proposed.

[Identification of the segment for binding of transferrin using a cellular receptor]. / Identifikatsiia uchastka sviazyvaniia transferrina s kletochnym retseptorom.

Methods of proteolysis, radio-immunoblotting and affinity chromatography were used for identifying the human transferrin molecular binding site with cellular receptor. Monoclonal antibody HTF-14 which inhibits binding of the transferrin molecule with the receptor was employed. We showed that this monoclonal antibody has an antigenic determinant of the conformational type which is localized on the COOH-sublobe of the NH2-lobe of the molecule of the transferrin.