Myo-inositol content in pteridophytes and the isolation and characterization of L-myo-inositol-1-phosphate synthase from Diplopterygium glaucum
Título del documento: Myo-inositol content in pteridophytes and the isolation and characterization of L-myo-inositol-1-phosphate synthase from Diplopterygium glaucum
Revista: Brazilian journal of plant physiology
Base de datos: PERIÓDICA
Número de sistema: 000276202
ISSN: 1677-0420
Autors: 1
2
3
Institucions: 1Darjeeling Government College, Department of Botany, Darjeeling. India
2Bengal College of Engineering and Technology, Department of Biotechnology, Bidhan Nagar, Durgapur. India
3Presidency College, Department of Botany, Calcuta, Bengala Occidental. India
Any:
Període: Abr-Jun
Volum: 18
Número: 2
Paginació: 291-298
País: Brasil
Idioma: Inglés
Tipo de documento: Artículo
Enfoque: Experimental, analítico
Resumen en inglés Myo-inositol is involved in normal growth and development of all living organisms and L-myo-inositol-1-phosphate synthase (MIPS; EC: 5.5.1.4) is responsible for its de novo synthesis. This enzyme has been reported for a number of life forms including plants, animals and bacteria. In the present study free myo-inositol has been detected in the common pteridophytes found in the Darjeeling Himalayas and the enzyme, L-myo-inositol-1-phosphate synthase has been partially purified from Diplopterygium glaucum (Thunb.) Nakai. A crude homogenate from the reproductive pinnules of D. glaucum was subjected to streptomycin sulphate precipitation and 0-70% ammonium sulphate fractionation followed by successive chromatography through DEAE-cellulose, Hexylagarose and BioGel A-0.5m columns. This resulted in a partial purification of the enzyme of about 81-fold with 13.5% recovery. The pteridophytic MIPS specifically utilized D-glucose-6-phosphte and NAD+ as its substrate and co-factor, respectively. It shows a pH optimum between 7.0 and 7.5 while the temperature maximum was 30 °C. The enzyme activity was stimulated by NH4+, slightly inhibited by Na+, Ba2+ and Cd2+, and strongly inhibited by Li+, Zn2+ and Hg2+. EDTA, pCMB and some substrate isomers like glucose-1-phosphate, fructose-6-phosphte and galactose-6-phosphate were inhibitory to the enzyme. The apparent molecular weight of the native D. glaucum MIPS was determined to be approximately 171 kDa
Resumen en portugués Myo-inositol está envolvido no crescimento e desenvolvimento de todos os organismos vivos e a enzima sintase do L-myo-inositol-1-fosfato (MIPS; EC: 5.5.1.4) é responsável pela sua síntese de novo. Esta enzima tem sido relatada em um número grande de plantas, animais e bactérias. No presente estudo myo-inositol não complexado foi detectado em pteridófitas comuns encontradas em Darjeeling Himalayas e a enzima sintase do L-myo-inositol-1-fosfato foi parcialmente purificada a partir de Diplopterygium glaucum (Thunb.) Nakai. Um extrato protéico não purificado de pinulas reprodutivas foi precipitada com sulfato de estreptomicina e 0-70% sulfato de amônia seguido de sucessivas cromatografias em colunas de DEAE-celulose, Hexylagarose e BioGel A. Este procedimento resultou na purificação parcial de 81 vezes, com recuperação de 13.5%. A MIPS dessa pteridófita usou especificamente D-glicose-6-fosfato and NAD+ como substrato e cofator, respectivamente. Mostrou pH ótimo entre 7,0 e 7,5, enquanto a temperatura ótima foi 30°C. A atividade da enzima foi estimulada por NH4+, pouco inibida por Na+, Ba2+ e Cd2+, e fortemente inibida por Li+, Zn2+ e Hg2+. EDTA, pCMB e alguns substratos isômeros, como glicose-1-fosfato, frutose-6-fosfato e galactose-6-fosfato inibiram a enzima. A massa molecular aparente da MIPS de D. glaucum é aproximadamente 171 kDa
Disciplines Biología,
Química
Paraules clau: Briofitas y pteridofitas,
Bioquímica,
Myo-inositol,
Diplopterygium glaucum,
Inositol,
Pteridophyta
Keyword: Biology,
Chemistry,
Bryophytes and pteridophytes,
Biochemistry,
Pteridophyta,
Diplopterygium glaucum,
Inositol,
Myo-inositol
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