Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/196078
Type: Artigo de periódico
Title: The Thermal Stability Of A Castor Bean Seed Acid Phosphatase.
Author: Granjeiro, Paulo Afonso
Cavagis, Alexandre Donizeti Martins
de Campos Leite, Luciana
Ferreira, Carmen Veríssima
Granjeiro, José Mauro
Aoyama, Hiroshi
Abstract: The effect of temperature on the activity and structural stability of an acid phosphatase (EC 3.1.3.2.) purified from castor bean (Ricinus communis L.) seeds have been examined. The enzyme showed high activity at 45 degrees C using p-nitrophenylphosphate (p-NPP) as substrate. The activation energy for the catalyzed reaction was 55.2 kJ mol(-1) and the enzyme maintained 50% of its activity even after 30 min at 55 degrees C. Thermal inactivation studies showed an influence of pH in the loss of enzymatic activity at 60 degrees C. A noticeable protective effect from thermal inactivation was observed when the enzyme was preincubated, at 60 degrees C, with the reaction products inorganic phosphate-P (10 mM) and p-nitrophenol-p-NP(10 mM). Denaturation studies showed a relatively high transition temperature (Tm) value of 75 degrees C and an influence of the combination of Pi (10 mM) and p-NP (10 mM) was observed on the conformational behaviour of the macromolecule.
Subject: Acid Phosphatase
Castor Bean
Enzyme Stability
Hot Temperature
Nitrophenols
Organophosphorus Compounds
Phosphates
Plant Proteins
Protein Denaturation
Seeds
Thermodynamics
Rights: fechado
Identifier DOI: 
Address: http://www.ncbi.nlm.nih.gov/pubmed/15646022
Date Issue: 2004
Appears in Collections:Artigos e Materiais de Revistas Científicas - Unicamp

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