Binding properties and immunolocalization of a fatty acid-binding protein in Giardia lamblia.
We describe here a fatty acid-binding protein (FABP) isolated and purified from the parasitic protozoon Giardia lamblia. The protein has a molecular mass of 8 kDa and an isoelectric point of 4.96. A Scatchard analysis of the data at equilibrium revealed a dissociation constant of 3.12 x 10(-8) M when the labeled oleic acid was displaced by a 10-fold greater concentration of unlabeled oleic acid. Testosterone, sodium desoxycholate, taurocholate, metronidazol, and alpha-tocopherol, together with butyric, arachidonic, palmitic, retinoic, and glycocholic acids, were also bound to the protein. Assays with polyclonal antibodies revealed that the protein is located in the ventral disk and also appears in the dorsal membrane, the cytoplasm, and in the vicinity of the lipid vacuoles.
Instituto de Biotecnología, Universidad de Granada, Campus Universitario de Fuentenueva, E-18071 Granada, Spain.
S M T
SM
Hassan
M
M
Maache
R Díaz
RD
de la Guardia
O M
OM
Córdova
J R Gil
JR
García
M
M
Galiana
D
D
Acuña Castroviejo
M
M
Martins
Antonio
A
Osuna
D000818:Animals; D002352:Carrier Proteins / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D002846:Chromatography, Affinity; D004591:Electrophoresis, Polyacrylamide Gel; D050556:Fatty Acid-Binding Proteins; D019084:Fluorescent Antibody Technique, Indirect; D016829:Giardia lamblia / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure; D007150:Immunohistochemistry; D047468:Immunoprecipitation; D007525:Isoelectric Focusing; D007526:Isoelectric Point; D016253:Microscopy, Immunoelectron; D008970:Molecular Weight; D015800:Protozoan Proteins / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D013050:Spectrometry, Fluorescence; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D002352:Carrier Proteins; D050556:Fatty Acid-Binding Proteins; D015800:Protozoan Proteins