Purification, kinetic properties and physicochemical characterization of a novel acid phosphatase (AP) from germinating peanut (Arachis hypogaea) seed.
Acid phosphatase activity was detected in peanut (Arachis hypogaea) cotyledons during germination. Four (4) to six (6) days of germination was the meantime corresponding to maximum hydrolytic activity of this enzyme. The understanding of the role of acid phosphatase activity during germination led to purify this enzyme by successive chromatography separations on DEAE-Sepharose CL-6B, Sephacryl S-100 HR and Phenyl-Sepharose HP to apparent homogeneity from germinated peanut cotyledon five days old. This enzyme designated peanut cotyledon acid phosphatase (AP) had native molecular weight of 24 kDa by gel permeation. SDS-PAGE of the purified acid phosphatase resolved a single protein band that migrated to approximately 21.5 kDa. Thus, this acid phosphatase likely functions as a monomer. The enzyme had optimum pH (5.0) and temperature (55 degrees C), and appeared to be stable in the presence of anionic, cationic and non-ionic detergents. Substrate specificity indicated that the purified acid phosphatase hydrolyzed a broad range of phosphorylated substrates. However, natural substrates such as ADP and ATP were the compounds with highest rate of hydrolysis for the enzyme. Moreover, the purified acid phosphatase exhibited phytase activity. These results showed that this enzyme played a peculiar role during germination, notably in reducing the rate of phytic acid, an antinutritional substance contained in peanut seed.
Gonnety
Jean Tia
JT
Laboratoire de Biochimie et Technologie des Aliments de I'Unité de Formation et de Recherche en Sciences et Technologie des Aliments de l'Université d'Abobo-Adjamé, Côte d'lvoire.
Niamké
Sébastien
S
Meuwiah Faulet
Betty
B
N'guessan Kouadio
Eugène Jean-Parfait
EJ
Kouamé
Lucien Patrice
LP
D010832:6-Phytase / Q000737:chemistry / Q000302:isolation & purification; D000135:Acid Phosphatase / Q000737:chemistry* / Q000302:isolation & purification*; D000244:Adenosine Diphosphate / Q000737:chemistry; D000255:Adenosine Triphosphate / Q000737:chemistry; D010367:Arachis / Q000201:enzymology*; D018548:Cotyledon / Q000201:enzymology*; D018525:Germination; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D010940:Plant Proteins / Q000737:chemistry* / Q000302:isolation & purification*; D013379:Substrate Specificity
D010940:Plant Proteins; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D000135:Acid Phosphatase; D010832:6-Phytase