Immobilization of alpha-galactosidase on galactose-containing polymeric beads

WOS: 000274773500007Industrial application of a-galactosidase requires efficient methods to immobilize the enzyme, yielding a biocatalyst with high activity and stability compared to free enzyme. An alpha-galactosidase from tomato fruit was immobilized on galactose-containing polymeric beads. The immobilized enzyme exhibited an activity of 0.62 U/g of support and activity yield of 46%. The optimum pH and temperature for the activity of both free and immobilized enzymes were found as pH 4.0 and 37 degrees C, respectively. Immobilized alpha-galactosidase was more stable than free enzyme in the range of pH 4.0-6.0 and more than 85% of the initial activity was recovered. The decrease in reaction rate of the immobilized enzyme at temperatures above 37 degrees C was much slower than that of the free counterpart. The immobilized enzyme shows 53% activity at 60 degrees C while free enzyme decreases 33% at the same temperature. The immobilized enzyme retained 50% of its initial activity after 17 cycles of reuse at 37 degrees C. Under same storage conditions, the free enzyme lost about 71% of its initial activity over a period of 7 months, whereas the immobilized enzyme lost about only 47% of its initial activity over the same period. Operational stability of the immobilized enzyme was also studied and the operational half-life (t(1/2) was determined as 6.72 h for p-nitrophenyl alpha-D-galactopyranoside (PNPG) as substrate. The kinetic parameters were determined by using PNPG as substrate. The K-m and V-max values were measured as 1.07 mM and 0.01 U/mg for free enzyme and 0.89 mM and 0.1 U/mg for immobilized enzyme, respectively. The synthesis of the galactose-containing polymeric beads and the enzyme immobilization procedure are very simple and also easy to carry out. (C) 2009 Elsevier Inc. All rights reserved

Examining the basic principles of quality by design (QbD) approach in analytical studies

Although the first application of Quality by Design (QbD) concept started for product development studies, the number of studies regarding its application to analytical development has been increased recently. Basically, QbD strategy in both formulation development and analytic studies are identical logically and conceptually, but they have some differences in terms of its terminology and application. Essential terminology and approach differences in this concept are; the determination of the analytic target profile, critical method characteristics, critical process parameters, and the determination of the method study area. However, the risk evaluation method which is necessary for the appropriate application of quality by design is also an inseparable part of the analytical quality by design. Despite those terminological differences, developing a quality-based method with the analytical design that contributes to research with an appropriately applied risk-based design quality approach and provides multiple advantages that will be noticed each and every time, will be useful both for researchers and authorities who investigate license documentation and changes. Therefore, the terminology which is used for analytic quality by design and appropriate risk evaluation approaches are explained in this study

Alpha-Amylase immobilized composite cryogels: some studies on kinetic and adsorption factors

*İnanan, Tülden ( Aksaray, Yazar )Stability of enzymes is a significant factor for their industrial feasibility. alpha-Amylase is an important enzyme for some industries, i.e., textile, food, paper, and pharmaceutics. Pumice particles (PPa) are non-toxic, natural, and low-cost alternative adsorbents with high adsorption capacity. In this study, Cu2+ ions were attached to pumice particles (Cu2+-APPa). Then, Cu2+-APPa embedded composite cryogel was synthesized (Cu2+-APPaC) via polymerization of gel-forming agents at minus temperatures. Characterization studies of the Cu2+-APPaC cryogel column were performed by X-ray fluorescence spectrometry (XRF), scanning electron microscopy (SEM), and Brunauer, Emmett, Teller (BET) method. The experiments were carried out in a continuous column system. alpha-Amylase was adsorbed onto Cu2+-APPaC cryogel with maximum amount of 858.7 mg/g particles at pH 4.0. Effects of pH and temperature on the activity profiles of the free and the immobilized alpha-amylase were investigated, and results indicate that immobilization did not alter the optimum pH and temperature values. k(cat) value of the immobilized alpha-amylase is higher than that of the free alpha-amylase while K-M value increases by immobilization. Storage and operational stabilities of the free and the immobilized alpha-amylase were determined for 35 days and for 20 runs, respectively

GENDER BUDGETING IN TURKEY: AN ASSESSMENT OF LOCAL PRACTICES FROM THE WELL-BEING PERSPECTIVE

This paper introduces the basic methodology and general findings of the research project entitled "Public Policies, Local Governments, Gender Budgeting: Women Friendly Cities, Case of Turkey". The aim of the project was to analyse public policies at the local level, the services and expenditures of the municipalities in particular from the gender well-being perspective. Main driver of the research was the expectation that promotion of gender mainstreaming in public policy design would have reflections in resource allocation in those pilot cities, which committed to the United Nations Joint Program-Women Friendly Cities Project (UNJP-WFCP) in Turkey since 2006. Five WFCP cities in different geographical regions (Kars, Sanliurfa, Nevsehir, Izmir, Samsun) were chosen and each was coupled with five neigbouring cities (Erzurum, Diyarbakir, Kayseri, Manisa, Ordu). Comparative analyses were conducted by: 1. gender auditing of policy documents; 2. cross-checking of perceptions of local service providers with those of local women beneficiaries; and 3. de-construction of municipality budgets on the basis of women's capabilities. Our well-being gender budgeting exercises showed that UNJP-WFCP cities were not much different from others in allocating funds to programmes that have the potential to enhance women's capabilities. We discuss the interaction of multiplicity of issues which need to be accounted for in assessments of current and prospective policy practices

First protein affinity application of Cu2+-bound pure inorganic nanoflowers

Today, a new kind of materials is introduced to separation media day by day to increase the efficiency of the separation processes, and multiple-petalled nanostructured materials are one of them. In this study, new pure inorganic copper phosphate nanoflowers (pCP-NFs) were synthesized, and some environmental conditions affecting on binding mechanism with human serum albumin were evaluated via changing medium pH, temperature, initial human serum albumin (HSA) amount and salt concentrations. Before experimental studies, pCP-NFs were subjected to some characterization tests such as scanning electron microscopy, energy-dispersive X-ray, X-ray diffraction and Fourier transform infrared spectroscopy. Besides a lot of valuable instrumental data, some obtained experimental ones as follows: after Cu2+ ions attachment to pCP-NFs as ligand, maximum HSA adsorption capacity of obtained Cu2+-pCP-NFs was found as 225.7 mg/g with an initial concentration of 1.5 mg/mL at pH 7 and 25 degrees C. Langmuir and Freundlich adsorption equations were evaluated for determination of appropriate adsorption model in interaction, and Langmuir model found as the fittest one with a R-2 of 0.9949 was also reviewed to determine Gibbs free energy between HSA and Cu2+-pCP-NFs interaction

Clinical importance of mean platelet volume in children diagnosed with Henoch-Schonlein purpura (Ig-A vasculitis)

Objectives: Henoch-Schonlein purpura (HSP) or IgA vasculitis, is the most common form of childhood vasculitis. Mean platelet volume (MPV) is a parameter of a complete blood count that shows thrombocyte function and activation. This study evaluated the link between MPV and HSP

Predictive Factors and Management of Steinstrasse After Shock Wave Lithotripsy in Pediatric Urolithiasis-A Multivariate Analysis Study

OBJECTIVE To define the predictive factors for the formation of steinstrasse (SS) after shock wave lithotripsy (SWL) and determine the treatment strategies for this complication in pediatric urolithiasis