RESUMEN
The GUT1 gene of the halotolerant yeast Pichia farinosa, encoding glycerokinase (EC 2.7.1.30), was expressed in Pichia pastoris. A purification factor of approximately 61-fold was achieved by a combination of nickel affinity and anion exchange chromatography. The specific activity of the final preparation was 201.6 units per mg protein with a yield of about 21%. A nearly homogeneous enzyme preparation was confirmed by SDS-polyacrylamide gels and mass spectrometry analysis. Glycerol stabilized the purified enzyme for long-term storage at -80°C. The pH and temperature optima were in the range of 6.5-7.0 and 45-50°C, respectively. ATP was the most effective phosphoryl group donor tested. Additionally, the enzyme phosphorylated glycerol also with ITP, UTP, GTP and CTP. The K(m) values of the enzyme for ATP and ITP were 0.428 and 0.845 mM, respectively. The kinetic properties of the enzyme with respect to UTP, GTP, and CTP suggested that glycerokinase exhibited negative cooperativity as double reciprocal plots showed a biphasic response to increasing nucleoside triphosphate concentrations. The application as a coupling enzyme in the determination of pyruvate kinase activity in cell extracts of Madin-Darby canine kidney cells showed good reproducibility when compared with a commercially available preparation of bacterial glycerokinase.
Asunto(s)
Proteínas Fúngicas/metabolismo , Glicerol Quinasa/metabolismo , Pichia/metabolismo , Proteínas Recombinantes de Fusión/metabolismo , Adenosina Trifosfato/metabolismo , Animales , Recuento de Células , Extractos Celulares , Línea Celular , Cromatografía de Afinidad , Cromatografía por Intercambio Iónico , Perros , Pruebas de Enzimas , Proteínas Fúngicas/química , Proteínas Fúngicas/genética , Glicerol/metabolismo , Glicerol Quinasa/química , Glicerol Quinasa/genética , Histidina/química , Histidina/genética , Histidina/metabolismo , Concentración de Iones de Hidrógeno , Cinética , Metanol/metabolismo , Oligopéptidos/química , Oligopéptidos/genética , Oligopéptidos/metabolismo , Pichia/química , Pichia/enzimología , Pichia/genética , Reacción en Cadena de la Polimerasa , Proteínas Recombinantes de Fusión/química , Proteínas Recombinantes de Fusión/genética , TemperaturaRESUMEN
Detailed description of the morphological and anatomic characteristics of Indian originating Kentjur plant (Kaempferia galanga L., Zingiberaceae family) which is cultivated in Java and the Sudan. In case of suspected falsification of the Kentjur powder by other Zingiberaceae rhizome powders or their starches it is difficult to differentiate. The quality determining components are described as well as the utilization as spice and medicinal herb.
Asunto(s)
Plantas Medicinales/química , Asia , Especias/análisisRESUMEN
Laboratory and clinical experience shows that after i.v. infusion of colloidal plasma volume expanders not only the wanted effect but unwanted side effects are to be expected as well. Besides Dextran and Gelatine, Hydroxyethyl starch is increasingly used. The author deals especially with possible anaphylactoid reactions after application of this new volume expander.
Asunto(s)
Anafilaxia/inducido químicamente , Derivados de Hidroxietil Almidón/efectos adversos , Sustitutos del Plasma/efectos adversos , Almidón/análogos & derivados , Anciano , Humanos , MasculinoRESUMEN
The author demonstrated column and paper chromatographically that no or very little amylose is extracted when using HAMPEL's method for the colorimetric determination of starch damage ("amylose number"). The actually extracted substances are mainly other starch components which form a violet colour on addition of a dilute iodine solution. Further starch components which form a violet colour on addition of a dilute iodine solution are extracted by rewashing with the different components of HAMPEL's solvent mixture. The most distinct results were obtained with distilled water. It is suggested to rewash the filter residue with distilled water to extract all the damaged starch and to use the combined extracts for the determination. In consideration of the fact that HAMPEL's solvent mixture extracts not only amylose from the damaged starch, the term of "amylose number" should be rejected and replaced by the term of formamide ammonium sulphate sulphosalicylic acid (FAS) method or formamide sodium sulphate sulphosalicylic acid (FNS) method.
Asunto(s)
Amilosa/análisis , Almidón , Cromatografía , Cromatografía en Papel , Colorimetría , Estudios de Evaluación como Asunto , Salicilatos , Solubilidad , Almidón/análisis , Almidón/normas , Triticum/análisis , Verduras/análisisRESUMEN
The problems arising in using microcrystalline cellulose in the food industry are outlined. Like starch granules, microcrystalline cellulose is also persorbed by the human and animal organism. As long as the problem persists whether persorption is a normal, everyday process or a process which is detrimental in the long run, the statement that the use of greater amounts of microcrystalline cellulose for foods and pharmaceutical products is absolutely safe should be carefully examined.