| Journal: | Brazilian journal of plant physiology |
| Database: | PERIÓDICA |
| System number: | 000276202 |
| ISSN: | 1677-0420 |
| Authors: | Chhetri, D.R1 Mukherjee, A.K2 Adhikari, J3 |
| Institutions: | 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 |
| Year: | 2006 |
| Season: | Abr-Jun |
| Volumen: | 18 |
| Number: | 2 |
| Pages: | 291-298 |
| Country: | Brasil |
| Language: | Inglés |
| Document type: | Artículo |
| Approach: | Experimental, analítico |
| English abstract | 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 |
| Portuguese abstract | 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 |
| Keyword: | Briofitas y pteridofitas, Bioquímica, Myo-inositol, Diplopterygium glaucum, Inositol, Pteridophyta |
| Keyword: | Biology, Chemistry, Bryophytes and pteridophytes, Biochemistry, Pteridophyta, Diplopterygium glaucum, Inositol, Myo-inositol |
| Full text: | Texto completo (Ver HTML) |
