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PubMed2002

Identification of the cellulose-binding and the cell wall-binding domains of Eubacterium cellulosolvens 5 cellulose-binding protein A (CBPA).

The cellulose-binding domain (CBD) and the cell wall-binding domain (CWBD) of Eubacterium cellulosolvens 5 cellulose-binding protein A (CBPA) have been determined. The gene (cbpA) encoding CBPA and its derivatives were expressed in Escherichia coli. We were able to obtain the eight recombinant proteins and examine for their cellulose-binding ability, cell wall-binding ability and carboxymethyl cellulase (CMCase) activity. Since five recombinant proteins, which contain the unknown domain (UD-2) located between two linker-like regions of CBPA, bound to cellulose, this region has been identified as the CBD. The CBD did not show a significant sequence similarity with any other CBDs. Moreover, the N-terminal region of CBPA showed a significant sequence similarity with a catalytic domain of glycosyl hydrolase family 9, and the recombinant proteins containing the region showed CMCase activity. Since the UD-3, which is located in the C-terminal region of CBPA, bound to the cell walls of E. cellulosolvens 5, the region has been identified as the CWBD. However, the CWBD did not show a significant sequence similarity with any other proteins previously reported.

Bacterial Proteins↗
PubMed2002

Specific adhesion to cellulose and hydrolysis of organophosphate nerve agents by a genetically engineered Escherichia coli strain with a surface-expressed cellulose-binding domain and organophosphorus hydrolase.

A genetically engineered Escherichia coli cell expressing both organophosphorus hydrolase (OPH) and a cellulose-binding domain (CBD) on the cell surface was constructed, enabling the simultaneous hydrolysis of organophosphate nerve agents and immobilization via specific adsorption to cellulose. OPH was displayed on the cell surface by use of the truncated ice nucleation protein (INPNC) fusion system, while the CBD was surface anchored by the Lpp-OmpA fusion system. Production of both INPNC-OPH and Lpp-OmpA-CBD fusion proteins was verified by immunoblotting, and the surface localization of OPH and the CBD was confirmed by immunofluorescence microscopy. Whole-cell immobilization with the surface-anchored CBD was very specific, forming essentially a monolayer of cells on different supports, as shown by electron micrographs. Optimal levels of OPH activity and binding affinity to cellulose supports were achieved by investigating expression under different induction levels. Immobilized cells degraded paraoxon rapidly at an initial rate of 0.65 mM/min/g of cells (dry weight) and retained almost 100% efficiency over a period of 45 days. Owing to its superior degradation capacity and affinity to cellulose, this immobilized-cell system should be an attractive alternative for large-scale detoxification of organophosphate nerve agents.

Bacterial Adhesion↗
PubMed1998

Roles of the catalytic domain and two cellulose binding domains of Thermomonospora fusca E4 in cellulose hydrolysis.

Thermomonospora fusca E4 is an unusual 90.4-kDa endocellulase comprised of a catalytic domain (CD), an internal family IIIc cellulose binding domain (CBD), a fibronectinlike domain, and a family II CBD. Constructs containing the CD alone (E4-51), the CD plus the family IIIc CBD (E4-68), and the CD plus the fibronectinlike domain plus the family II CBD (E4-74) were made by using recombinant DNA techniques. The activities of each purified protein on bacterial microcrystalline cellulose (BMCC), filter paper, swollen cellulose, and carboxymethyl cellulose were measured. Only the whole enzyme, E4-90, could reach the target digestion of 4.5% on filter paper. Removal of the internal family IIIc CBD (E4-51 and E4-74) decreased activity markedly on every substrate. E4-74 did bind to BMCC but had almost no hydrolytic activity, while E4-68 retained 32% of the activity on BMCC even though it did not bind. A low-activity mutant of one of the catalytic bases, E4-68 (Asp55Cys), did bind to BMCC, although E4-51 (Asp55Cys) did not. The ratios of soluble to insoluble reducing sugar produced after filter paper hydrolysis by E4-90, E4-68, E4-74, and E4-51 were 6.9, 3.5, 1.3, and 0.6, respectively, indicating that the family IIIc CBD is important for E4 processivity.

Amino Acid Sequence↗
PubMed1998

Connective tissue formation in subcutaneous cellulose sponge implants in the rat. The effect of the size and cellulose content of the implant.

Granulation tissue formation was studied in viscose cellulose sponges with different cellulose contents and sizes after subcutaneous implantation in rats. Samples were removed and studied histologically and histomorphometrically 1-16 weeks after implantation. The implants with lower cellulose content and smaller size were invaded by more cells and filled with connective tissue more rapidly than those with the higher content and larger size. In larger sponge implants the beneficial effect of the lower cellulose content was more conspicuous.

Animals↗
PubMedDate not supplied

New method for covalent immobilization of proteins to cellulose and cellulose derivatives.

Cellulose and microcrystalline cellulose are treated consecutively with sodium periodate and urea. The interaction of urea derivatives with formaldehyde results in highly reactive groups, capable of further condensation with the amino acid residues of the proteins. The condensation of chymotrypsin, pepsin, and ovomucoid with such activated matrices has been studied in the pH interval 2 to 10. Differences have been found in the binding properties of basic and acid proteins. Satisfactory values have been obtained concerning the relative enzymatic and inhibitory activity of the immobilized products with respect to high- and low-molecular substrates. Chymotrypsin, immobilized on microcrystalline cellulose matrix, is found to manifest better catalytic properties compared with chymotrypsin immobilized on cellulose matrix. A probable sequence of the stages of chemical activation of the matrices and covalent binding of the proteins to them has been proposed. The main advantages of the proposed method consist of the high reactivity of the binding group in a wide pH range, its suitable length, and its easy synthesis.

Cellulose↗
PubMed1999

Cloning of cellulose synthase genes from Acetobacter xylinum JCM 7664: implication of a novel set of cellulose synthase genes.

Three sets of cellulose synthase genes were cloned from a cellulose-producing bacterium Acetobacter xylinum JCM 7664. One set of genes (bcsAI/bcsBI/bcsCI/bcsDI) were highly conserved with the well-established type I genes in other strains of A. xylinum, while the other two (bcsABII-A, bcsABII-B) were homologous to the known type II (acsAII). Unexpectedly, they were immediately followed by a gene cluster of bcsX/bcsY/bcsCII/ORF569, likely forming an operon. Western blotting demonstrated that the BcsY protein accumulated in cells. Since BcsY showed striking similarities to a number of membrane-bound transacylases, it was hypothesized that the type II cellulose synthase produces acylated cellulose, which might be anchored on the cytoplasmic membrane. An insertion sequence of IS1380-type was found just upstream of the one type II gene (bcsABII-B), suggestive of nonfunctioning.

Amino Acid Sequence↗
PubMed1975

The Site of Cellulose Synthesis: Cell Surface and Intracellular beta-1, 4-Glucan (Cellulose) Synthetase Activities in Relation to the Stage and Direction of Cell Growth.

beta-1, 4-Glucan (cellulose) synthetase activity (UDP-glucose: beta-1, 4-glucan-glucosyl transferase) present at cell surfaces of growing regions of Pisum sativum epicotyl was assayed by supplying UDP-(14)C-glucose directly to thin slices of tissue. Initial rates of glucosyl transfer under these conditions approached the rates of cellulose deposition observed in vivo in intact tissue at various stages of growth. Normal tissue homogenization procedures destroyed the high surface activity, although a small amount of residual activity (3-10% of total) could be detected in particulate fractions. In homogenates from elongating tissue, the residual activity was almost entirely associated with Golgi membrane. In homogenates of tissue which had ceased elongating, whether because of normal maturation or treatment with ethylene (or high levels of auxin), the activity was present in Golgi plus a membrane fraction rich in smooth endoplasmic reticulum vesicles. It is suggested that cellulose synthetase activity associated with these two organelles represents intracellular enzyme in transit to specific sites of cellulose synthesis and microfibrillar orientation at the cell surface.

Journal Article↗
PubMed1994

CEL1: a novel cellulose binding protein secreted by Agaricus bisporus during growth on crystalline cellulose.

The cel1 gene of Agaricus bisporus encodes a protein (CEL1) that has an architecture resembling the multi-domain fungal cellulases, although the sequence of its putative catalytic core is not matched by any other in the protein and nucleic acid data bases. The N-terminal half of the putative catalytic domain of CEL1 was expressed in Escherichia coli as a fusion protein with glutathione-S-transferase. The fusion protein was used to raise a CEL1-specific antibody. CEL1 was detected as an extracellular 49.8 kDa protein in A. bisporus cellulose-grown cultures, where it bound strongly to cellulose. CEL1 was neither an endoglucanase, a cellobiohydrolase able to hydrolyze fluorogenic cellobiosides, a beta-glucosidase, a xylanase, nor a cellobiose: quinone oxidoreductase. CEL1 was present in some fractions of culture fluid separated by electrophoresis which released soluble sugars from crystalline cellulose.

Agaricus↗
PubMed2005

Concurrent microscopic observations and activity measurements of cellulose hydrolyzing and methanogenic populations during the batch anaerobic digestion of crystalline cellulose.

This study compares process data with microscopic observations from an anaerobic digestion of organic particles. As the first part of the study, this article presents detailed observations of microbial biofilm architecture and structure in a 1.25-L batch digester where all particles are of an equal age. Microcrystalline cellulose was used as the sole carbon and energy source. The digestions were inoculated with either leachate from a 220-L anaerobic municipal solid waste digester or strained rumen contents from a fistulated cow. The hydrolysis rate, when normalized by the amount of cellulose remaining in the reactor, was found to reach a constant value 1 day after inoculation with rumen fluid, and 3 days after inoculating with digester leachate. A constant value of a mass specific hydrolysis rate is argued to represent full colonization of the cellulose surface and first-order kinetics only apply after this point. Additionally, the first-order hydrolysis rate constant, once surfaces were saturated with biofilm, was found to be two times higher with a rumen inoculum, compared to a digester leachate inoculum. Images generated by fluorescence in situ hybridization (FISH) probing and confocal laser scanning microscopy show that the microbial communities involved in the anaerobic biodegradation process exist entirely within the biofilm. For the reactor conditions used in these experiments, the predominant methanogens exist in ball-shaped colonies within the biofilm.

Anaerobiosis↗
PubMed1989

Cloning of a gene involved in cellulose biosynthesis in Acetobacter xylinum: complementation of cellulose-negative mutants by the UDPG pyrophosphorylase structural gene.

Three cellulose-negative (Cel-) mutants of Acetobacter xylinum strain ATCC 23768 were complemented by a cloned 2.8 kb DNA fragment from the wild type. Biochemical analysis of the mutants showed that they were deficient in the enzyme uridine 5'-diphosphoglucose (UDPG) pyrophosphorylase. The analysis also showed that the mutants could synthesize beta(1-4)-glucan in vitro from UDPG, but not in vivo from glucose. This result was expected, since UDPG is known to be the precursor for cellulose synthesis in A. xylinum. In order to analyze the function of the cloned gene in more detail, its biological activity in Escherichia coli was studied. These experiments showed that the cloned fragment could be used to complement an E. coli mutant deficient in the structural gene for UDPG pyrophosphorylase. It is therefore clear that the cloned fragment must contain this gene from A. xylinum. This is to our knowledge the first example of the cloning of a gene with a known function in cellulose biosynthesis from any organism, and we suggest the gene be designated celA.

Cellulose↗
PubMed2005

Degradation of cellulose by the bean-pathogenic fungus Colletotrichum lindemuthianum. Production of extracellular cellulolytic enzymes by cellulose induction.

Colletotrichum lindemuthianum was able to grow and produce extracellular cellulolytic activity in a defined medium containing cellulose as the main carbon substrate. As measured either by the hydrolysis of 4-methylumbelliferyl-beta-D -cellotrioside or the release of glucose from carboxymethylcellulose, activity reached a peak after 13 days of incubation and then declined whereas growth markedly increased afterwards. Detection of glucose in carboxymethylcellulose hydrolysates suggested the concerted operation of endo-1,4-beta-glucanase, cellobiohydrolase (exo-1,4-beta-glucanase) and beta-glucosidase activities. The highest levels of cellulolytic activity were obtained in media supplemented with cellulose and glutamate. Other carbon and nitrogen sources markedly influenced growth and enzyme production. Oligonucleotides homologous to specific regions of the cellobiohydrolase-encoding cbhII gene from Trichoderma reesei were used to isolate a C. lindemuthianum cbhII-DNA fragment whose sequence revealed homologies of 98% and 92% with the nucleotide and the deduced amino acid sequences of the corresponding cbhII-DNA of T. reesei, respectively. RT-PCR and Southern blot analyses of total RNA samples obtained from cellulose-grown but not from glucose-grown mycelium revealed the expression of the corresponding cbhII transcript. The cbhII-cDNA fragment was cloned and sequenced.

Amino Acid Sequence↗
PubMed1989

Addition of cloned beta-glucosidase enhances the degradation of crystalline cellulose by the Clostridium thermocellum cellulose complex.

A thermostable beta-glucosidase from Clostridium thermocellum which is expressed in Escherichia coli was used to determine the substrate specificity of the enzyme. A restriction map of the beta-glucosidase gene cloned in plasmid pALD7 was determined. Addition of the E. coli cell extract (containing the beta-glucosidase) to the cellulase complex from C. thermocellum increased the conversion of crystalline cellulose (Avicel) to glucose. The increase was specifically due to hydrolysis of the accumulated cellobiose. A cellulose degradation process using beta-glucosidase to assist the potent cellulase complex of C. thermocellum, as shown here can open the way for industrial saccharification of cellulose to glucose.

Cellulase↗
PubMed1994

A streptavidin-cellulose-binding domain fusion protein that binds biotinylated proteins to cellulose.

A fusion protein, Sta-CBDCex, which comprises streptavidin with a cellulose-binding domain (CBDCex) fused to its C terminus, was produced in the cytoplasm of Escherichia coli, where it formed inclusion bodies. Renatured Sta-CBDCex, recovered from the inclusion bodies, adsorbed to Avicel, a microcrystalline cellulose. The cellulose-bound Sta-CBDCex in turn bound biotinylated alkaline phosphatase or biotinylated beta-glucosidase. The immobilized beta-glucosidase remained fully active during 2 weeks of continuous column operation at 50 degrees C.

Biotin↗
PubMed1992

Improvement of blood compatibility on cellulose dialysis membrane. I. Grafting of 2-methacryloyloxyethyl phosphorylcholine on to a cellulose membrane surface.

A methacrylate with a phospholipid polar group, 2-methacryloyloxyethyl phosphorylcholine (MPC), was grafted on cellulose membrane for haemodialysis in an aqueous medium using cerium ion (Ce4+) as an initiator. The effects of the concentrations of MPC and Ce4+, and degassing of feed solution on the grafting of MPC on the surface and the membrane properties such as permeability and mechanical strength were examined. The grafted MPC composition depended on the concentrations of both the monomer and initiator in the feed solution. When the grafted MPC distribution was controlled by the monomer concentration, the permeability of the membrane decreased with an increase in grafted MPC distribution. On the other hand, the permeability was not changed from the original membrane's value when the MPC distribution was regulated by Ce4+ concentration. The tensile strength of the membrane did not change during the grafting of MPC and this indicated that the grafting had taken place in the amorphous region of the cellulose. These results suggested that this method is a promising way to improve the blood compatibility of a cellulose membrane without having an adverse effect on the haemodialysis membrane.

Biocompatible Materials↗
PubMed1975

Cellulose synthesis by Acetobacter xylinum. II. Investigation into the relation between cellulose synthesis and cell envelope components.

Cell envelope fractions, capable of cellulose synthesis from uridine diphosphate glucose, alpha-glucose-1-phosphate, glucose-6-phosphate and glucose, have been isolated from Acetobacter xylinum suspensions and various enzymatic properties examined. Essential enzymes were found to be distributed throughout the cell envelope region, with both inner (cytoplasmic) and outer (cell wall) membranes contributing to cellulose synthesis. The central role of UDPG in cellulose synthesis was confirmed and the results indicated that the nucleoside diphosphate sugar functions solely in the cell envelope region of whole cells. A comparison of properties of the cell envelope system with those of different preparations used by other workers, suggested that the method of cell disruption may influence substrate specificity.

Cell Membrane↗
PubMed2000

Near IR spectroscopy to quantify the silica content and difference between silicified microcrystalline cellulose and physical mixtures of microcrystalline cellulose and silica.

Silicified microcrystalline cellulose (SMCC) has been shown to have advantages over conventional microcrystalline cellulose (MCC). These advantages are (i) improved tablet strength compared to that achieved with MCC, (ii) the retention of compressibility after wet granulation, whereas MCC produces weaker tablets after wet granulation, and (iii) superior flow properties than MCC. In this study near IR spectroscopy has been used to study MCC, SMCC (with different loadings of colloidal silicon dioxide, CSD) and physical mixtures of MCC and CSD. It was found that even though SMCC and MCC were very similar, there was a region of the near IR spectra (second derivative peak at 2194 nm) where a distinctive response was seen for SMCC. The size of the peak was proportional to the CSD content for the co-processed SMCC samples. The peak was not present to the same extent for physical mixtures. A combination of near IR and a test for total silica content would make it possible to discern whether microcrystalline cellulose samples were SMCC material or simple physical mixtures.

Cellulose↗
PubMed2001

Cellulose: how many cellulose synthases to make a plant?

Many questions remain about the biosynthesis of cellulose, the major plant cell wall component, not least of which is why plants have so many genes for the cellulose synthase catalytic subunit. Perhaps multiple isoforms of cellulose synthase are needed in the same cell for the formation of functional dimeric complexes.

Arabidopsis↗
PubMed2003

Studies on the mechanisms of leukocyte adhesion to cellulose acetate beads: an in vitro model to assess the efficacy of cellulose acetate carrier-based granulocyte and monocyte adsorptive apheresis.

Granulocyte and monocyte adsorptive apheresis (GMA) using a column filled with cellulose acetate (CA) beads (carriers) has been associated with a significant clinical efficacy in patients with rheumatoid arthritis and ulcerative colitis. To obtain further understanding on the mechanisms of disease modification by cellulose acetate-carrier-based GMA, in the present study, we investigated the mechanisms of granulocyte and monocyte adhesion to CA beads following exposure of human peripheral blood to the carriers at 37 degrees C for up to 60 min under controlled conditions. Cellulose acetate beads selectively adsorbed granulocytes, monocytes. CD19+ (B cells) and CD56+ (NK cells) lymphocyte subpopulations. The granulocyte and monocyte adsorption was inhibited by heat-inactivated plasma and EDTA, indicating that the adsorption was plasma protein (immunoglobulin, complement) and calcium dependent. Accordingly, granulocyte and monocyte adsorption was markedly enhanced by coating the carriers with IgG. Similarly, C3b was adsorbed onto the CA beads as a marker of complement activation. The results indicated that IgG and active complement fragments mediated leukocyte adhesion to CA beads via the FcgammaR and/or leukocyte complement receptor like CR3. Additionally, CA beads induced loss of expression of TNF receptors on CD16- granulocytes and CD14+ monocytes, but not on CD3+ lymphocytes In conclusion, CA beads might be an appropriate biomaterial for inducing extracorporeal immunomodulation as a treatment for auto-immune diseases which are associated with pathological leukocyte activity.

Blood Component Removal↗