Effect of chemical modifications of myelin basic protein on its interaction with lipid interfaces and cell fusion ability

Summary The ability of native and chemically modified myelin basic protein to induce fusion of chicken erythrocytes and to interact with lipids in monolayers at the air-water interface and liposomes was studied. Chemical modifications of myelin basic protein were performed by acetylation and succinylation: the positive charges of the native protein were blocked to an extent of about 90–95%.Cellular aggregation and fusion of erythrocytes into multinucleated cells was induced by the native myelin basic protein. This effect was diminished for both acetylated and succinylated myelin basic protein. Native myelin basic protein penetrated appreciably in sulphatide-containing lipid monolayers while lower penetration occurred in monolayers of neutral lipids. Contrary to this, both chemically modified myelin basic proteins did not show any selectivity to penetrate into interfaces of neutral or negatively charged lipids. The intrinsic fluorescence of the native and chemically modified myelin basic proteins upon interacting with liposomes constituted by dipalmitoylphosphatidycholine, glycosphingolipids, egg phosphatidic acid or dipalmitoylphosphatidyl glycerol was studied. The interaction with liposomes of anionic lipids is accompanied by a blue shift of the maximum of the native protein emission fluorescence spectrum from 346 nm to 335 nm; no shift was observed with liposomes containing neutral lipids. The acetylated and succinylated myelin basic proteins did not show changes of their emission spectra upon interacting with any of the lipids studied. The results obtained in monolayers and the fluorescence shifts indicate a lack of correlation between the ability of the modified proteins to penetrate lipid interfaces and the microenvironment sensed by the tryptophan-containing domain.Abbreviations MBP myelin basic protein - DPPC dipalmitoyl phosphatidylcholine - DPPG dipalmitoyl phosphatidylglycerol - PA phosphatidic acid     

Preparation of liposomes entrapping a high specific activity of 111In3+-bound inulin

Targeting liposomes to specific tissues or cells require the unequivocal determination of the uptake of liposomes at the cellular level. The present report describes the preparation of liposomes entrapping a high specific activity of 111In3+-bound inulin, and the potential applications of a multiple labeling technique for characterizing the extent of uptake of liposomes by tissues or different cells in a given tissue in vivo. The labeling method involves the application of the technique of acetylacetone-mediated, ionophoric loading of 111In3+ into liposomes entrapping an inulin derivative to which a strong chelating agent, diethylenetriamine-pentaacetic acid (DTPA), is bound. Subsequent ionophoric removal of the weakly bound 111In3+ by incubating the previously 111In3+-loaded liposomes with 10 mM nitrilotriacetic acid and 100 microM tropolone at room temperature for 20 min results in the preparation of liposomes entrapping 111In3+-DTPA-inulin. Our method of preparation yields net efficiencies of converting 63-78% of the externally added 111In3+ to liposome-entrapped 111In3+-DTPA-inulin.     

Liposome uptake by cultured macrophages mediated by modified low-density lipoproteins

We have investigated effects of native low-density lipoproteins (LDL) and malondialdehyde-treated LDL on the interaction of 5(6)-carboxyfluorescein-labeled liposomes bearing antibodies to LDL with cultured J774 macrophages. It was found that an addition of modified LDL to the incubation medium resulted in 15-20-fold increase of carboxyfluorescein binding to cells, whereas native LDL did not produce such effect. The increase of carboxyfluorescein binding to macrophages in the presence of modified LDL was not due to an enhanced leakage of the label from liposomes. The modified-LDL-mediated binding of carboxyfluorescein to cells was reduced to 20-30% of the initial level in the presence of cell-respiration inhibitors (NaF and antimycin A). Fluorescent microscopy data also indicate the modified-LDL-induced incorporation of liposome contents into cells. The results obtained in this study make it possible to assume that in the presence of malondialdehyde-treated LDL, liposomes with antibodies to LDL may be incorporated into macrophages via the receptor-mediated pathway for modified LDL.     

盐酸洛拉曲克脂质体的制备及其质量考察

目的：制备盐酸洛拉曲克脂质体并考察其理化特性。方法：采用薄膜挤压-硫酸铵梯度法制备盐酸洛拉曲克脂质体,透射电镜及激光粒度分析仪分别观察和检测其粒径大小及分布,通过紫外分光光度法测定包封率及评估体外释药试验。结果：制备的盐酸洛拉曲克脂质体包封率达83.6%±2.37%,粒径103.5±26nm且分布均匀。24h体外释放实验结果提示约有66.5%的盐酸洛拉曲克从脂质体释放出来。结论：新制备的盐酸洛拉曲克脂质体粒径大小均匀,包封率尚有提高空间,具有体外缓慢释药的特性。     

Evaluation of quantitative parameters of the interaction of antibody-bearing liposomes with target antigens

The model system for the analysis of targeted liposomes is proposed--the layer of protein antigen adsorbed on polystyrene wells. Antibodies were treated with palmitoyl chloride and liposomes were produced by the cholate dialysis method in the presence of the modified protein (7 X 10(-4) mol protein/mol lipid). Affinity of antibody-bearing liposomes to the antigen on the surface of Multiwell plates was studied, and apparent dissociation constant value was estimated: KD was in the range 1.5 to 5 X 10(-9) M liposomes. Sequential transfers of liposomes in antigen-coated plates revealed that the high-affinity fraction of liposomes is adsorbed first. The bound fraction has 1.7-times-higher protein content. For effective in vivo targeting it would be necessary to have high-affinity liposomes and a high concentration of the target antigen.     

Interaction of liposomes with human leukocytes in whole blood

The uptake of multilamellar liposomes into human leukocytes in whole blood in vitro was evaluated on the basis of the cellular association of liposomal markers (3H-labelled cholesterol, lipid phase; [14C]inulin, aqueous phase). The entry of liposomes into human blood leukocytes was linear for 60 min and was mediated by a saturable mechanism displaying affinity constants of 0.28 +/- 0.17 and 0.16 +/- 0.05 mM liposomal lipid (means +/- S.E.) for liposomal lipid and aqueous phase markers, respectively. Amicon filtration analysis of incubation mixtures containing blood and liposomes (phosphatidylcholine:dicetyl phosphate:cholesterol, 70:20:10) showed that 34% of [14C]inulin was lost (neither liposome-associated nor cell-associated) after 60 min. By preincorporating sphingomyelin (35 mol%) into multilamellar liposomes, the leakage of the model aqueous phase marker inulin was reduced to 8% after 60 min, thus enhancing the drug carrier potential of liposomes in blood. As a consequence of their interaction with liposomes, the polymorphonuclear leukocytes in whole blood decreased in apparent buoyant density, while maintaining their viability. These results indicate that blood leukocytes in their natural milieu of whole blood are capable of interacting with, and taking up multilamellar liposomes.     

Binding of antibodies in liposomes to extracellular matrix antigens

We have incorporated antibodies against fibronectin or laminin into liposomes and studied their interaction with insoluble forms of these antigens. The antibodies, after modification by palmitoylchloride, were incorporated into the lipid bilayer by the cholate dialysis method. The antibodies in the liposomes recognized their specific antigen with little reaction to the alternative attachment protein or to albumin (less than 2%). The binding of antibody-containing liposomes to insoluble antigen was inhibited by soluble antibodies to the respective antigens but not by antibodies to other antigens. The affinity constant of the liposome-antibody complex with the antigen was estimated at 1-10 X 10(-9) M liposomes. Thus, antibodies in liposomes retain their reactivity and specificity, and the reaction constant is comparable to that observed for immune complexes.     

Enzyme replacement via liposomes. Variations in lipid compositions determine liposomal integrity in biological fluids.

Liposomes survive exposure to biological fluids poorly, extruding trapped enzymes, drugs, or solutes upon interaction with serum or plasma constituents. We have quantified the disruptive effects of human serum on liposomes and have studied whether various modifications in their phospholipid composition might produce liposomes with an increased carrier potential for application in vivo. Multilamellar liposomes (phosphatidycholine 70:dicetyl phosphate 20:cholesterol 10) were prepared with 3H-labeled phosphatidylcholine as the lipid phase marker and [14C]inulin and horseradish peroxidase as aqueous phase markers. Gel exclusion chromatography showed that 32 +/- 3% of [14C]inulin and 27 +/- 7% of horseradish peroxidase were lost after 1 h incubation with 10% (v/v) human serum. Loss of aqueous solutes was reduced to 20 +/- 5%/h and 17 +/- 2%/h, respectively, after treatment with decomplemented serum (56 degrees C, 30 min). Loss induced by serum was concentration and time dependent: to 57 +/- 2% at 1 h and 67 +/- 14% at 24 h, with 50% serum; plasma was slightly less perturbing whereas human serum albumin was not at all disruptive. By incorporating sphingomyelin (35 mol%) into multilamellar liposomes, the leakage of [14c]-inulin in the presence of 10% serum was reduced to 12 +/- 4%/h; increasing the molar percentage of cholesterol to 35% also stabilized the lipid bilayers, reducing leakage to 20 +/- 7%/h. Both small and large unilamellar vesicles could not be stablilized against serum-mediated leakage by the incorporation of sphingomyelin. The data suggest that cholesterol and sphingomyelin enhance liposomal integrity in the presence of serum or plasma and promise to yield enhanced survival of drug-laden lipid vesicles in biological fluids in vivo.     

Transfer of condensed viral DNA into eukaryotic cells using proteoliposomes

High-molecular-weight viral DNAs have been packed into proteoliposomes prepared by reverse-phase evaporation followed by phospholipid membrane targeting by influenza virus glycoprotein bound to hydrophobic 'anchors'. DNA has been encapsulated in the form of spermine condensates--toroidal structures sized approx. 0.1 micron, resistant to ultrasound. The efficiency of entrapping into liposomes reached 30% for condensed DNA of Mr up to 3 X 10(7). Specific infectivity of simian virus 40 DNA and simian adenovirus DNA packed into such proteoliposomes was 50- to 100-fold higher than that shown by free DNA preparations under Ca.phosphate-precipitation conditions.     

Antigen presentation by liposomes bearing class II MHC and membrane IL-1

Liposomes containing membrane IL-1, Iak, and the antigen conalbumin were evaluated as "synthetic antigen presenting cells." The role of these three molecules in macrophage-T cell interaction was studied by testing their ability to induce the proliferation of a T-cell clone specific to conalbumin (the D10 cell line) or immune spleen cells sensitized three times in vivo with conalbumin. In the latter case, splenic macrophages were eliminated by adherence and a lysomotropic agent. The antigen conalbumin was presented on the surface of the liposomes as native undigested protein. When the liposomes presented native conalbumin, Iak, and membrane IL-1, significant proliferation occurred, but if the liposomes lacked membrane IL-1, the proliferation of the T-cell clone and the spleen cells reached only about 60 percent of the previous signal. Native conalbumin and class II antigen alone were required for T-cell activation, while membrane IL-1 only amplified the response. When the liposomes were made with only Iak and membrane IL-1, lacking conalbumin, there was no proliferation of antigen-specific target cells. These results indicated that in this synthetic system, membrane IL-1 increases the magnitude of the response but is not essential for the proliferative response of antigen-specific T cells.     

靶向树突状细胞表面分子DEC-205长循环免疫脂质体稳定性模型的构建及其生物学特性

应用多相分散体系的动力稳定性和聚结稳定性理论,以薄膜分散法构建了靶向树突状细胞（dendritic cells,DCs）表面分子DEC-205长循环免疫脂质体（anti—DEC-205 iLPSM）的稳定性模型,并对其物理稳定性、生物学特性等进行了考察。结果表明经优化后的脂质体4℃贮存7d后粒径分布变化较小;FTTC-dextran累积泄漏率小于7％;耦联抗DEC-205的免疫脂质体（anti—DEC-205 iLPSM）可特异性地识别DCs,并作为良好载体将FITC-dextran带入DCs浆内。anti—DEC-205 iLPSM模型的构建为进一步研究抗原靶向DEC-205受体后的体内免疫应答情况提供了工作基础,有望开发一种新型DCs疫苗应用于临床。     

Liposomes in immunology

Liposomes, the artificial phospholipid vesicles, have the capacity of entrapping water soluble substances in their aqueous compartments. Of the many possible potentials of liposomes their application in immunology is most significant. Recent studies have shown an adjuvant and a carrier effect of liposomes to a number of antigens. Liposomes used in these studies are generally multilamellar vesicles with the antigen encapsulated in the aqueous phase. Some antigens may also be associated with the lipid lamellae covalently or noncovalently. The adjuvant property of liposomes is greatly affected by the surface charge of the vesicle as well as the site of association of the antigen. The other factors which may have a role in immunopotentiation by liposomes are the size and structure of the vesicles, the lipid composition, route of administration and their surface sugars. In addition, liposomes may function as carriers to haptens and other antigens. In association with liposomes the nature of the immune response may be modulated. For a further enhancement of the adjuvant activity of liposomes use has been made of immunomodulators.     

Introduction of purified hexosaminidase A into Tay-Sachs leukocytes by means of immunoglobulin-coated liposomes.

To determine whether ligand-receptor interactions could engender the selective uptake by deficient cells of enzyme-laden liposomes, aggregated human IgG was used to coat liposomes which had previously trapped purified hexosaminidase A (Hex A). By a new, high-yield procedure, Hex A was purified 7000-fold from human placenta: the homogeneous protein had a pI of 5.4, permitting nonelectrostatic trapping in the aqueous interstices of anionic multilamellar liposomes (molar ratios of phosphatidyl-choline-dicetyl phosphate-cholesterol, 7:2:1). Trapped Hex A was separated from free enzyme by means of Sephadex G-200 chromatography: 1.3 +/- 0.3 mUnits of Hex A/mumol of phospholipid became associated with liposomes and trapped glucose, utilized as a marker of the aqueous compartment. Once sequestered, the enzyme remained latent until lamellae were disrupted by Triton X-100. Presence of enzyme in aqueous compartments was proved by the demonstration of increased trapping (0.02-1.33 mUnits/mumol of phospholipid) with increments in like-sign repulsion of the bilayers produced by increasing molar ratios of anionic dicetyl phosphate (5-20%). To provide for ligand-receptor interaction with surface Fc receptors of human polymorphonuclear leukocytes (PMN's), liposomes were coated by heat-aggregated (62 degrees C, 10 min) human IgG. PMN's from Tay-Sachs patients genetically deficient in Hex A activity readily incorporated exogenous Hex A provided in this fashion. PMN's exposed to enzyme-laden liposomes coated with aggregated IgG incorporated significantly more Hex A than when the enzyme was presented in uncoated liposomes or in liposomes coated with native IgG, which engages Fc receptors with less avidity. Free enzyme was not endocytized. Acquisition of specific Hex A isozyme activity by cells (determined by DEAE-cellulose chromatography) was not due to surface adsorption since cytochalasin B, which prevents phagocytosis but not surface adherence; blocked uptake. Incorporation of the isozyme by deficient cells was also demonstrated by starch gel electrophoresis, and ultrastructural studies showed that the immunoglobulin-coated, Hex A-containing liposomes were taken up into PMN lysosomes after membrane fusion. The studies indicate that liposomes coated with surface ligands may be used to introduce enzyme or other materials into deficient cells possessing appropriate surface receptors.     

Opioid peptide interactions with lipid bilayer membranes.

The interaction of the delta-opioid receptor selective peptides, cyclic [D-Pen2, D-Pen5]-enkephalin [DPDPE] and its acyclic analog, DPDPE(SH)2, with neutral phospholipid bilayer membranes was examined by permeability and calorimetry measurements. The permeabilities were accomplished by entrapping either peptide inside of unilamellar liposomes (composed of a mixture of a molar ratio 65:25:10 phosphatidylcholine/phosphatidylethanolamine/cholesterol) then monitoring the peptide efflux through the bilayer. The initial permeability of DPDPE (first 12 h) averaged over four experiments was (0.91 +/- 0.47).10(-12) cm s-1. In contrast the average permeability of the acylic DPDPE(SH)2 was (4.26 +/- 0.23).10(-12) cm s-1. The effect of these peptides on the phase transition, Tm, of 1,2-dipalmitoylphosphatidylcholine (DPPC) bilayers was examined by high sensitivity differential scanning calorimetry. The Tm, the calorimetric enthalpy, and the van 't Hoff enthalpy of DPPC were not significantly altered by the presence of DPDPE, whereas the calorimetric data for DPPC with DPDPE(SH)2 showed a small, yet significant, increase (0.2 degrees C) in the Tm with a 30% decrease in the cooperative unit. Both the permeability and calorimetry data reveal a stronger peptide-membrane interaction in the case of the more flexible acyclic peptide.     

Stabilization of retinol through incorporation into liposomes

Chemical and photochemical processes during storage and preparation rapidly degrade retinol, the most active form of vitamin A. Therefore, the efficacy of incorporation into liposomes in order to modulate the kinetics of retinol degradation was investigated. Retinol was readily incorporated into multilamellar liposomes that were prepared from soybean phosphatidylcholine; the extent of the incorporation was 98.14 +/- 0.93% at pH 9.0 at a ratio of 0.01 : 1 (wt : wt) retinol : phospholipid. It was only marginally lower at higher retinol concentrations. The pH of the hydration buffer had a small effect. The incorporation efficiency ranged from 99.25 +/- 0.47% at pH 3 to 97.45 +/- 1.13% at pH 11. The time course of the retinol degradation in the aqueous solution in liposomes was compared to that of free retinol and free retinol with alpha-tocopherol under a variety of conditions of pH (3, 7, and 11), temperature (4, 25, 37, and 50 degrees ), and light exposure (dark, visible, and UV). The retinol that was incorporated into the liposomes degraded significantly slower than the free retinol or retinol with alpha-tocopherol at pH 7 and 11. At pH 3, where the free retinol degrades rapidly, the degradation kinetics were similar in liposomes and the presence of alpha-tocopherol. At pH 7.0 and 4 degrees in the light, for example, free aqueous retinol was completely degraded within 2 days, while only 20% of the retinol in the liposomes were degraded after 8 days. In general, the protective effect of the liposome incorporation was greater at low temperatures, at neutral and high pH, and in the dark. The results suggest that protection is greater in the solid, gel phase than in the fluid liquid crystalline phase lipids. These results indicate that the incorporation into liposomes can extend the shelf-life of retinol under a variety of conditions of temperature, pH, and ambient light conditions.     

Incorporation of the protective antigen of Brucella abortus into liposomes and the immunogenic properties of the antigen-containing liposomes

The incorporation of B. abortus protective antigen into liposomes and its localization in liposomes have been found to depend on the lipid composition of liposomes. After the injection of the protective antigen conjugated with negatively charged liposomes humoral response is more pronounced than after the injection of the protective antigen incorporated into neutral liposomes. The immunization of guinea pigs with antigen-containing liposomes ensures the production of "incomplete antibodies" in the animals in high titers.     

Quantitative fluorescence measurement of chloride transport mechanisms in phospholipid vesicles

A quantitative fluorescence assay has been developed to measure Cl flux across liposomal membranes for use in chloride transporter reconstitution studies. A Cl-sensitive fluorophore [6-methoxy-N-(3-sulfopropyl)quinolinium; SPQ] was entrapped into phospholipid/cholesterol liposomes formed by bath sonication, high-pressure extrusion, and detergent dialysis. Liposomes containing entrapped SPQ were separated from external SPQ by passage down a Sephadex G25 column. There was less than 10% leakage of SPQ from liposomes in 8 h at 4 degrees C and in 2 h at 23 degrees C. Cl influx (JCl in millimolar per second or nanomoles per second per centimeter squared) was determined from the time course of SPQ fluorescence, measured by cuvette or stopped-flow fluorometry, in response to inward Cl gradients. In 90% phosphatidylcholine (10% cholesterol liposomes at 23 degrees C, JCl in response to a 50 mM inward Cl gradient was 0.06 +/- 0.01 mM.s-1 (SD, n = 3) in the absence and 0.27 +/- 0.02 mM.s-1 in the presence of a K/valinomycin voltage clamp (0 mV), showing that the basal Cl "leak" is conductive; JCl increased (1.7 +/- 0.1)-fold in the presence of a 60-mV inside-positive diffusion potential. Accuracy of chloride influx rates determined by the SPQ method was confirmed by measurement of 36Cl uptake. In liposomes voltage-clamped to 0 mV, JCl was linear with external [Cl] (0-100 mM), independent of pH gradients, and strongly dependent on temperature (activation energy 18 +/- 1 kcal/mol, 12-42 degrees C) as predicted for channel-independent Cl diffusion.(ABSTRACT TRUNCATED AT 250 WORDS)     

Thrombolysis using liposomal-encapsulated streptokinase: an in vitro study

The clot-lysing ability of streptokinase (SK) was examined using membrane-bound thrombi. Encapsulation of SK in large unilamellar phospholipid vesicles (liposomes) resulted in entrapping approximately 30% of its original activity. Measurements of streptokinase activity for liposomal-encapsulated streptokinase (LESK) indicated little loss of activity or leakage in Tris-buffered saline over a 24-hr period at temperatures of 4 and 23 degrees C. However, incubation of free SK and LESK in platelet-poor plasma (PPP) at 37 degrees C resulted in a decrease of SK activity. The retention of SK activity in LESK was considerably higher than that of unentrapped SK. Clot-dissolving time (CDT) was measured by monitoring the pressure drop during slow filtration in plasma through membrane-bound thrombi. The results indicated that both LESK and free SK were able to activate the fibrinolytic system. Without prior incubation in PPP at 37 degrees C, the CDT of a SK and PPP mixture (SK/PPP) was 10.7 +/- 1.9 min (n = 12), while that of a LESK and PPP mixture (LESK/PPP) was 12.4 +/- 1.7 min (n = 12). The CDT-detected clot-lysing abilities of both SK and LESK were diminished by incubation in PPP, but to different extents. After 15- and 30-min incubations, the CDT of SK/PPP increased significantly to 15.5 +/- 1.5 and 24.1 +/- 2.4 min (n = 5, P less than 0.05), respectively. In contrast, the CDT of LESK/PPP increased to 13.3 +/- 0.8 min (n = 5) after 15 min of incubation and to 16.0 +/- 1.1 min (n = 5, P less than 0.05) after a 30-min incubation. These results suggest that entrapment of SK in liposomes preserves the thrombolytic potential of the plasminogen activator by limiting its exposure to the components of the plasma.     

The reaction of hydrogen peroxide with the dimethyl ester heme derivative of cytochrome c peroxidase

A modified cytochrome c peroxidase was prepared by reconstituting apocytochrome c peroxidase with protoheme in which both heme propionic acid groups were converted to the methyl ester derivatives. The modified enzyme reacted with hydrogen peroxide with a rate constant of (1.3 +/- 0.2) x 10(7) M-1 s-1, which is 28% that of the native enzyme. The reaction between the modified enzyme and hydrogen peroxide was pH-dependent with an apparent pK of 5.1 +/- 0.1 compared to a value of 5.4 +/- 0.1 for the native enzyme. These observations support the conclusion that the apparent ionization near pH 5.4, which influences the hydrogen peroxide-cytochrome c peroxidase reaction is not due to the ionization of the propionate side chains of the heme group in the native enzyme. A second apparent ionization, with pK of 6.1 +/- 0.1, influences the spectrum of the modified enzyme which changes from a high spin type at low pH to a low spin type at high pH.     

Novel immobilized liposomal glucose oxidase system using the channel protein OmpF and catalase

The reactivity of immobilized glucose oxidase-containing liposomes (IGOL) prepared in our previous work (Wang et al. [2003] Biotechnol Bioeng 83:444-453) was considerably improved here by incorporating the channel protein OmpF from Escherichia coli into the liposome membrane as well as by entrapping inside the liposome's aqueous interior not only glucose oxidase (GO), but also catalase (CA), both from Aspergillus niger. CA was used for decomposing the hydrogen peroxide produced in the glucose oxidation reaction inside the liposomes. The presence of OmpF enhanced the transport of glucose molecules from the exterior of the liposomes to the interior. In a first step of the work, liposomes containing GO and CA (GOCAL) were prepared and characterized. A remarkable protection effect of the liposome membrane on CA inside the liposomes at 40 degrees C was found; the remaining CA activity at 72 h incubation was more than 60% for GOCAL, while less than 20% for free CA. In a second step, OmpF was incorporated into GOCAL membranes, leading to the formation of OmpF-embedded GOCAL (abbreviated GOCAL-OmpF). The activity of GO inside GOCAL-OmpF increased up to 17 times in comparison with that inside GOCAL due to an increased glucose permeation across the liposome bilayer, without any leakage of GO or CA from the liposomes. The optimal system was estimated to contain on average five OmpF molecules per liposome. Finally, GOCAL-OmpF were covalently immobilized into chitosan gel beads. The performance of this novel biocatalyst (IGOCAL-OmpF) was examined by following the change in glucose conversion, as well as by following the remaining GO activity in successive 15-h air oxidations for repeated use at 40 degrees C in an airlift bioreactor. IGOCAL-OmpF showed higher reactivity and reusability than IGOL, as well as IGOL containing OmpF (IGOL-OmpF). The IGOCAL-OmpF gave about 80% of glucose conversion even when the catalyst was used repeatedly four times, while the corresponding conversions were about 60% and 20% for the IGOL and IGOL-OmpF, respectively. Due to the absence of CA, IGOL-OmpF was less stable and resulted in drastically inhibited GO.