Ch. Schleicher et Ja. Santome, PURIFICATION, CHARACTERIZATION, AND PARTIAL AMINO-ACID SEQUENCING OF AN AMPHIBIAN LIVER FATTY-ACID-BINDING PROTEIN, Biochemistry and cell biology, 74(1), 1996, pp. 109-115
The fatty acid binding protein (FABP) from toad liver cytosol was puri
fied to homogeneity by a procedure involving gel filtration and anion
exchange chromatography. The protein presented a molecular mass of 13
987 +/- 2 daltons determined by electrospray mass spectrometry. Native
isoelectric focusing of the purified liver FABP revealed a single pI
6.8 band. On the other hand, the toad heart FABP showed a different mo
bility than that of load liver FABP by both sodium dodecyl sulfate pol
yacrylamide gel electrophoresis and isoelectric focusing. Moreover, to
ad liver FABP cross-reacted with antisera to mammalian liver FABP but
not with antisera to heart FABP. The difference between toad liver and
heart FABPs was further confirmed by partial ami no acid sequencing.
As the N-terminus of toad liver FABP was blocked, the protein was chem
ically and enzymatically cleaved and the resulting peptides were subje
cted to automated Edman degradation. Partial amino acid sequencing sho
wed that the toad liver FABP is related to that of mammalian liver and
is clearly different from the amphibian heart FABP as well as from th
e amphibian intestine FABP.