Different sensitivity of the sarcoplasmic reticulum Ca(2+)-ATPase enzyme to fluorescein-isothiocyanate in rabbit and carp muscles.
1. Carp and rabbit sarcoplasmatic reticulum Ca(2+)-ATPase enzymes were compared with respect to their sensitivity to FITC labelling. 2. The carp enzyme showed much lower sensitivity to FITC in the Ca(2+)-Mg2+ activated ATPase activity. Fifty percent inhibition was observed at 20 microM labelling FITC concentration; in rabbit enzyme this inhibition was already achieved at 2 microM FITC. 3. The tryptic cleavage products of the carp enzyme identified with immunoblot analysis as well as with FITC fluorescence, suggest multiple cleavage, yielding different fragments from the ones well known in rabbit and in rat enzyme. 4. The present results indicates major structural differences with respect to the FITC binding, and tryptic cleavage between the SR Ca(2+)-ATPase enzymes from carp and rabbit, despite the cross-reactivity with polyclonal antibodies.
Hieu
L H
LH
Department of Biochemistry, A. József University, Szeged, Hungary.
Nemcsók
J
J
Molnár
E
E
Dux
L
L
D000818:Animals; D001665:Binding Sites; D000252:Calcium-Transporting ATPases / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*; D002347:Carps; D016650:Fluorescein-5-isothiocyanate; D007120:Immunochemistry; D009132:Muscles / Q000201:enzymology; D011817:Rabbits; D012519:Sarcoplasmic Reticulum / Q000201:enzymology*; D013045:Species Specificity; D014357:Trypsin
D014357:Trypsin; D000252:Calcium-Transporting ATPases; D016650:Fluorescein-5-isothiocyanate