Effect of the cosolvent type on the extraction of α-amylase with reversed micelles: Circular dichroism study

Chang, Qing-Long; Chen, Jiayong; Zhang, Xiufang; Zhao, Nanming

doi:10.1016/s0141-0229(96)00088-9

Cited by 24 publications

(17 citation statements)

References 10 publications

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“…The errors involved in calculating the percentages of secondary structure were estimated at about ±5%. These secondary structure results were very close to the literature values ( -helix: 21.3%, -sheet: 22.9% and coil: 55.8%) (Chang et al, 1997), thereby indicating that the purified amylase folded with a reasonable secondary structure.…”

Section: Secondary Structure Analysissupporting

confidence: 88%

Isolation and characterization of a cold-active amylase from marine Wangia sp. C52

Liu¹,

Zhang²,

Dang³

et al. 2011

Afr. J. Microbiol. Res.

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Amylase activity was detected in the culture medium of marine Wangia sp. C52, which was isolated from the Southern Okinawa Trough deep-sea sediment. In the present study, a cold-active amylase was purified to homogeneity from the culture broth by ammonium sulfate precipitation and gel filtration chromatography. The molecular mass of the amyalse was 58 kDa, and its isoelectric point was close to 5.6. The optimal pH and temperature were 30°C and 6.0, respectively. In the presence of Ca 2+ and Co 2+ , the enzyme activity was stimulated while Cu 2+ , Hg 2+ , Mn 2+ , Zn 2+ , Fe 3+ , Al 3+ , EDTA, EGTA and SDS reduced the activity. K m and V max values of the purified enzyme for soluble starch were 2.08 ± 0.3 mg/ml and 1.26 ± 0.02 mg/ml/min, respectively. The final purified enzyme had -helix of 25%, -sheet of 26% and random coil of 49%, consistent with the theoretical values. This showed that the purified amylase folded with a reasonable secondary structure.

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Section: Secondary Structure Analysissupporting

confidence: 88%

Isolation and characterization of a cold-active amylase from marine Wangia sp. C52

Liu¹,

Zhang²,

Dang³

et al. 2011

Afr. J. Microbiol. Res.

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“…They are easy to scale up, have a high efficiency, can be made selective, have a low energy demand, and can be operated continuously [7,8,[10][11][12][13][14]. They can also offer moderate thermal conditions for processing of biomaterials [5,9].…”

Section: Introductionmentioning

confidence: 99%

Penicillin G solubilisation into AOT reverse micelles

Mohd‐Setapar

Wakeman

Tarleton

2009

Chemical Engineering Research and Design

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Extraction of penicillin G from an aqueous phase into an organic phase containing AOT reverse micelles has been investigated. The extraction is influenced by the initial penicillin G concentration, the salt type and concentration in the aqueous phase, pH, and surfactant concentration. The results show that penicillin is an interfacially active compound that interacts with AOT, with the interfacial association being dependent on both pH and surfactant concentration. When the concentration ratio [P] aq /[S] is high precipitation of the penicillin occurs. The distribution coefficient favours transfer of the penicillin into the reverse micelles at moderate AOT concentrations. The distribution coefficient at infinite dilution, K  , is shown to be a function of both pH and surfactant concentration; similar trends in the value of K  were observed at different pH values; K  decreases as the surfactant concentration is increased. Reverse micelle formation affects the volume of water transferred into the organic phase; from measurements of the water transferred, the size of the reverse micelles was estimated to be about 3 nm and the number of AOT molecules per reverse micelle about 360.

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“…The transfer of proteins from aqueous phase to the reverse micelles is primarily due to the electrostatic interactions between proteins and the surfactants. Since the last decades, researchers have studied the extraction of proteins based on affinity interaction using reverse micellar solutions formed by nonionic surfactants (Guadalupe et al, 1992;Chang et al, 1997;Naoe et al, 1998;Ichikawa et al, 2000;. By incorporating affinity ligands into the system, proteins can be selectively extracted by a biospecific affinity interaction.…”

Section: Introductionmentioning

confidence: 99%

Liquid - liquid extraction of matrine using TRPO/cyclohexane reverse micelles

Dong

Zhou

Kang

et al. 2009

Braz. J. Chem. Eng.

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-Reverse micellar extraction has been widely used in the purification of biomolecules. However, reverse micelles formed by ionic surfactants can only be employed for the extraction of biomolecules that are charged in the extraction system with the electrostatic interaction between surfactants and solutes as the driving force. In this study, the extraction of matrine by using reverse micelles formed by non-ionic TRPO surfactants was studied. Theoretical analysis and experimental results demonstrated that the driving force of the extraction is the coordination forces between matrines and TRPOs. Using this coordination-based reverse micellar extraction, matrine can be efficiently separated from oxymatrine and other components in the raw matrine materials. Experimental studies showed that the factors affecting matrine extraction include pH value and TRPO concentration. The existence of ions in the system does not affect the partition coefficient significantly and the addition of a small amount of chloroform in the solution of reverse micelles was found to improve the extraction significantly.

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Effect of the cosolvent type on the extraction of α-amylase with reversed micelles: Circular dichroism study

Cited by 24 publications

References 10 publications

Isolation and characterization of a cold-active amylase from marine Wangia sp. C52

Isolation and characterization of a cold-active amylase from marine Wangia sp. C52

Penicillin G solubilisation into AOT reverse micelles

Liquid - liquid extraction of matrine using TRPO/cyclohexane reverse micelles

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