In vitro evaluation of leptin fragments activity on the ob receptor.
In an attempt to identify regions in the leptin molecule responsible for its bioactivity, we tested six related-leptin peptide fragments denoted: Ac-hLEP(23-47)-NH(2) (I), Ac-hLEP(48-71)-NH(2) (II), Ac-hLEP(72-88)-NH(2) (III), Ac-hLEP(92-115)-NH(2) (IV), Ac-[Ser(117)]-hLEP(116-140)-NH(2) (V), Ac-hLEP(141-164)-NH(2) (VI) and their correspondent disulfide bridged dimer forms. The activity of the fragments was evaluated in comparision to leptin, by their ability to interact with leptin receptor using a cytosensor microphysiometer. Our results indicated that the fragments IV and V and [D-Leu(4)]-OB(3) and its human sequence analog were recognized by leptin receptor present in HP-75 cells, in agreement with the results obtained by other workers, validating that this region of the molecule contain the functional epitope of the leptin molecule.
de Oliveira
Vani Xavier
VX
Natural and Human Science Center, Federal University of ABC, Santo André, SP, Brazil. vani.junior@ufabc.edu.br
Fázio
Marcos Antonio
MA
Santos
Edson Lucas
EL
Pesquero
João Bosco
JB
Miranda
Antonio
A
D000595:Amino Acid Sequence; D002460:Cell Line; D002942:Circular Dichroism; D019281:Dimerization; D000939:Epitopes / Q000737:chemistry / Q000235:genetics / Q000494:pharmacology; D005110:Extracellular Space / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D020738:Leptin / Q000737:chemistry / Q000235:genetics / Q000494:pharmacology*; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000737:chemistry / Q000235:genetics / Q000494:pharmacology; D020836:Protein Structure, Quaternary; D054411:Receptors, Leptin / Q000187:drug effects* / Q000378:metabolism
D000939:Epitopes; C515448:LEPR protein, human; D020738:Leptin; D010446:Peptide Fragments; D054411:Receptors, Leptin