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Schizophyllan (SCH) is a high molecular weight homopolysaccharide composed of a β-(1,3)-D-glucan main chain with branching β-(1,6)-bound D-glucose residues. It forms triple helices that are highly stable towards heat and extreme pH, which provides SCH with interesting properties for industrial and medical applications. The recombinant anti-SCH antibody JoJ48C11 recognizes SCH and related β-(1,6)-branched β-(1,3)-D-glucans, but details governing its specificity are not known. Here, we fill this gap by determining crystal structures of the antigen binding fragment (Fab) of JoJ48C11 in the apo form and in complex with the unbranched β-(1,3)-D-glucose hexamer laminarihexaose 3.0 and 2.4 Å resolution, respectively. Together with docking studies, this allowed construction of a JoJ48C11/triple-helical SCH complex, leading to the identification of eight amino acid residues of JoJ48C11 (Tyr27H, His35H, Trp47H, Trp100H, Asp105H; Asp49L, Lys52L, Trp90L) that contribute to the recognition of glucose units from all three chains of the SCH triple helix. The importance of these amino acids was confirmed by mutagenesis and ELISA-based analysis. Our work provides an explanation for the specific recognition of triple-helical β-(1,6)-branched β-(1,3)-D-glucans by JoJ48C11 and provides another structure example for anti-carbohydrate antibodies.

Schizophyllan belongs to the β-1,3-glucan family and can form a complex with particular polynucleotides.1 We applied this complexation to specifically separate polynucleotides by constructing a schizophyllan-appended column. The column trapped poly(C) and poly(A), while it did not show any affinity to poly(G), which is consistent with the experimental results obtained in the homogenous solution. The present results indicate that the s-SPG column can be a new separation device for biomolecules.

Generally partially hydrolyzed polyacrylamides (HPAM) are used worldwide for polymer-based oil recovery processes. However there aree some problems associated with HPAM applications such as, treatment of produced water, oil-water separation and toxicity issues associated with degradation products of HPAM. Schizophyllan biopolymer is biodegradable and environmental friendly alternative to chemical polymers used for EOR applications. In present work we studied the schizophyllan production by fungi Schizophyllum commune ATCC38548, its structural characterization and potential applications in Microbial Enhanced Heavy Oil Recovery (MEOR). Different minimal production media containing carbohydrate based carbon sources were screened for better biopolymer production. During the course of experiments we studied microbial growth profile, biopolymer production, and rheological properties of biopolymer, chemical characterization and application of biopolymer in enhancing heavy oil recovery using Berea sandstone cores. The biopolymer was produced in significant quantities and increased the viscosity of the production medium after 9 days of incubation. Viscosities were measured using rheometer at different shear rates (0.1-100 s-1) and temperatures, where it was found to be isothermal over a wide range of temperature with strong shear thinning behavior. After 14 days of incubation, the viscosity was 21535 – 43 cP at shear rate from 0.1 – 100 s-1, respectively. Thermogravimetric analysis (TGA) analysis showed that the moisture content in purified biopolymer was 6.3%; it was quite stable till 100-200 °C and melted at temperatures higher than 250 °C. It was characterized as schizophyllan by MALDI-TOF-MS and NMR (1H and proton decoupled 13C NMR) analysis. The repeating tetrasaccharide unit of schizophyllan structure comprised of homoglucan with β-1, 3-linked backbone and single β-1, 6-linked laterally glucose side chains at every third residue. The biopolymer was used for MEOR experiments at 45 °C, using Berea sandstone core plugs. The biopolymer injection resulted in 28% additional heavy oil recovery over residual oil saturation (Sor).

Schizophyllan (SPG) is a kind of beta-1,3-glucan which has glucose side chain through a beta-1,6-glycosil bond (Fig. 1). It was found that SPG could form complex with single stranded polynucleotides. SPG forms triple stranded complex with single stranded RNAs thorough hydrogen bonding and hydrophobic interaction. It was found tht polynucleotide was protected from nuclease attacking to form the complex with SPG, and SPG enhanced antisense efficient.

beta-(1,6)-Branched beta-(1,3)-D-glucans like schizophyllan from the basidiomycete Schizophyllum commune excite various immunostimulatory effects and have been clinically tested as adjuvants. Some of the glucans are also applicable in food or petrol industry due to their viscosity and temperature stability in aqueous solution. Antibodies against these glucans could be used as tool for analysis of glucan preparations or for further research of its bioactivity. Therefore, an immune phage display library was constructed from mice immunized with schizophyllan. Three recombinant monoclonal antibodies were isolated from this library by affinity selection (panning) on schizophyllan. The half-maximal effective concentration (EC50) values for those antibodies varied between 16.4 ng mL−1 and 21.3 ng mL−1. The clones showed binding specificity not only for schizophyllan but also for other beta-(1,6)-branched beta-(1,3)-D-glucans of similar macromolecular structure. Denaturation of the secondary structure led to a reduced antibody binding, indicating an epitope requiring the correct conformation of the triple helical structure of the glucans.

Schizophyllan is a natural polysaccharide that has shown great potential as enhanced oil recovery (EOR) polymer for high-temperature, high-salinity reservoirs. Nevertheless, the adsorption behavior of schizophyllan over carbonate minerals remains ambiguous element towards its EOR applications. Here, we investigate the adsorption of schizophyllan on different carbonate minerals. The effect of mineral type, salinity, and background ions on adsorption is analyzed. Our results indicate the adsorption capacity is higher on calcite and dolomite compared to silica and kaolin and the adsorption capacity decreases with salinity. Moreover, the adsorption kinetics follows pseudo-second order mechanism regardless of the mineral type. Adsorption over calcite is diminished in presence of water structure making ions and enhanced in presence of structure breaking ion and in presence of urea. Gel permeation chromatography results reveal the preferential adsorption of longer chains. The adsorption over carbonate minerals proceed via complex formation between polymer molecule and mineral surface.

The β-1.3/1.6 glucan schizophyllan is a fungal polysaccharide that is known to suppress tumor growth. Thermoreversible, optically transparent gels of schizophyllan were obtained on addition of sorbitol to aqueous solutions of schizophyllan. Gel temperatures were independent of the history of sample preparation. The gelation process was followed by low-amplitude oscillatory shear and by static and dynamic light scattering. Power law behavior of storage modulus G′(ω) and loss modulus G″(ω) was found at the gel temperature with the exponent n=0.5. The static LS measurements showed a strong irregularity at the gel temperature. The intensity time correlation functions (TCFs) as measured by dynamic LS during the gelation process were transformed into the electric field TCFs, taking into account the heterodyne contributions. At the gel temperature which was estimated by rheology, DSC and static LS, no power law was found for the TCF. The angular dependence of the intensity TCF was measured and converted to the field TCF by use of a non-ergodicity treatment and by the heterodyne approximation, respectively. Both methods result in mean relaxation times that agree quite well. Two relaxation modes were found in the whole temperature range (above and below the gel temperature) indicating the existence of inhomogeneities in the gel.

(1986). Correlation between the Antitumor Activity of Schizophyllan and Its Triple Helix. Agricultural and Biological Chemistry: Vol. 50, No. 9, pp. 2415-2416.