A biomolecular recognition approach for the functionalization of cellulose with gold nanoparticles

Materials with new and improved functionalities can be obtained by modifying cellulose with gold nanoparticles (AuNPs) via the in situ reduction of a gold precursor or the deposition or covalent immobilization of pre‐synthesized AuNPs. Here, we present an alternative biomolecular recognition approach to functionalize cellulose with biotin‐AuNPs that relies on a complex of 2 recognition elements: a ZZ‐CBM3 fusion that combines a carbohydrate‐binding module (CBM) with the ZZ fragment of the staphylococcal protein A and an anti‐biotin antibody. Paper and cellulose microparticles with AuNPs immobilized via the ZZ‐CBM3:anti‐biotin IgG supramolecular complex displayed an intense red color, whereas essentially no color was detected when AuNPs were deposited over the unmodified materials. Scanning electron microscopy analysis revealed a homogeneous distribution of AuNPs when immobilized via ZZ‐CBM3:anti‐biotin IgG complexes and aggregation of AuNPs when deposited over paper, suggesting that color differences are due to interparticle plasmon coupling effects. The approach could be used to functionalize paper substrates and cellulose nanocrystals with AuNPs. More important, however, is the fact that the occurrence of a biomolecular recognition event between the CBM‐immobilized antibody and its specific, AuNP‐conjugated antigen is signaled by red color. This opens up the way for the development of simple and straightforward paper/cellulose‐based tests where detection of a target analyte can be made by direct use of color signaling.     

Metabolism of dulcitol in Euonymus japonica

Dulcitol-1(6)-¹⁴C was administered to leaves of E. japonica and samples were taken for time periods ranging from 0·5 to 24 hr. For each time period the absolute activity of the glucose, galactose and dulcitol pools was determined. Such studies demonstrated that dulcitol is converted to glucose and galactose. The initial product was glucose, some of which was converted to galactose, glacturonic acid and glucuronic acid. Fractionation of a leaf sample into its pectin, lignin, hemicellulose and α-cellulose components, with subsequent hydrolysis, showed that the dulcitol pool is used in the synthesis of structural carbohydrates. The activity of these fractions was shown to reside in dulcitol, glucose, galactose, galacturonic acid and glucuronic acid residues.     

Glycoconjugates are stage- and position-specific cell surface molecules in the developing olfactory system, 1: The CC1 immunoreactive glycolipid defines a rostrocaudal gradient in the rat vomeronasal system

Primary sensory neurons in the vomeronasal organ (VNO) project axons to the glomeruli of the accessory olfactory bulb (AOB) where they form connections with mitral cell dendrites. We demonstrate here that monoclonal antibodies to specific carbohydrate antigens define stage- and position-specific events during the development of the vomeronasal system (VN). CC1 monoclonal antibodies react with specific N-acetyl galactosamine containing glycolipids. In the embryo, CC1 antigens are expressed throughout the VNO and on vomeronasal nerves. Beginning approximately at birth and continuing into adults, CC1 expression is spatially restricted in the VNO to centrally located cell bodies. In the postnatal AOB, CC1 is expressed in the nerve layer and glomeruli, but only in the rostral half of the AOB. These data suggest that CC1 antigens may participate in the targeting of axons from centrally located VNO neurons to rostral glomeruli in the AOB. In contrast, CC2 monoclonal antibodies, which recognize complex α-galactosyl and α-fucosyl glycoproteins and glycolipids, react with all VNO cell bodies and VN nerves from embryonic (E) day 15 to adults. CC2 antibodies do not distinguish rostral from caudal regions of the AOB, nor are the CC2 glycoconjugates developmentally regulated. P-Path monoclonal antibodies, which recognize 9-O-acetyl sialic acid, react with cell bodies in the VNO and nerve fibers from E13 to postnatal (P) day 2. P-Path immunoreactivity disappears from the VNO system almost completely by P14, when only a few P-Path reactive nerve fibers can be seen. These studies suggest that specific cell surface glycoconjugates may participate in spatially and temporally selective cell–cell interactions during development and maintenance of vomeronasal connections.     

Carbohydrate Concentration in Pine as Affected by Inoculation with Bursaphelenchus xylophilus

Pines responded to inoculation with Bursaphelenchus xylophilus by changes in reducing and nonreducing carbohydrate concentrations dependent on the pine species and the pathotype of B. xylophilus with which the trees were inoculated. Carbohydrate concentrations, in compatible pine-nematode pathotype combinations, decreased initially after inoculation and then increased slightly before decreasing to approximately 10% of the control levels as the seedlings wilted. In compatible nematode pathotype-pine species combinations, carbohydrate concentrations decreased and then increased as the nematode population densities declined.     

On-line estimation of biomass concentration during transient growth on yeast chemostat culture using light reflectance

The application of light reflectance for estimating biomass concentration was investigated on oxidative chemostat culture of Saccharomyces cerevisiae. A correlation between light reflectance and dry weight was established for biomass concentrations from 0.5 to 10 g l^–1. The light reflectance signal was stable during the course of chemostat culture and proved to be sensitive to slight but fast changes in biomass concentration following shift-up in dilution rate, acetate pulse or during an oscillation. On-line estimated biomass revealed a larger time window of the biological response during spontaneous oscillations and could be used to predict carbohydrate storage.     

Glycosylated equine prolactin and its carbohydrate moiety

Glycosylated equine prolactin (G-ePRL) and nonglycosylated ePRL were purified to homogeneity from side fractions obtained during isolation of LH/FSH from horse pituitaries. Both PRL forms were isolated together in high yield by the isolation procedure used for glycosylated porcine PRL/(G-pPRL) and pPRL, involving acetone extraction/precipitation, NaCl and isoelectric precipitation, and gel filtration. Purification of G-ePRL required additional Con A chromatography. The N-terminal amino acid sequencing for 32 cycles of G-ePRL and ePRL resulted in sequences identical to the known primary structure of ePRL. Based on MALDI mass spectrometry analysis and SDS-PAGE mobilities,G-ePRL and ePRL had estimated molecular weights of 25,000 and 23,000 Da, respectively. G-ePRL displayed only 60% of the immunoreactivity of ePRL in homologous radioimmunoassay. Using the Nb2 lymphoma cell bioassay, ePRL was found to have about l/30th the mitogenic activity of bovine PRL; G-ePRL was approximately l/10th as active as ePRL. Glycosylation of G-ePRL at Asn³¹ was confirmed by isolation and sequence analysis of an enzymatically derived G-ePRL glycopeptide spanning residues 29–37. Monosaccharide compositions of intact G-ePRL and this glycopeptide were very similar (Man₃, GlcNAc₂, GalNAc₁, Fuc_0.6, Gal_0.2, NeuAc_0.15) and resembled that of G-pPRL. The glycopeptide contained one sulfate residue as determined by ion chromatography after acid hydrolysis, indicating the presence of a sulfated monosaccharide. Comparative carbohydrate analysis of G-ePRL and other G-PRL preparations suggests that the functionally significant Asn³¹ carbohydrate unit is a fucosylated complex mono- and/or biantennary oligosaccharide terminating with a sulfated GalNAc residue and two or three Man residues.     

Embigin/basigin subgroup of the immunoglobulin superfamily: Different modes of expression during mouse embryogenesis and correlated expression with carbohydrate antigenic markers

Embigin and basigin are highly glycosylated transmembrane glycoproteins with two immunoglobulin domains and form a subgroup in the immunoglobulin superfamily. Previous studies have demonstrated the functional significance of these molecules. In the present study, in situ hybridization analysis of their expression was performed during mouse embryogenesis. Embigin was strongly expressed in the endoderm during early postimplantation embryogenesis, and in the somite stage in the gut and visceral endoderm. Embryonic ectoderm and its derivative tissues weakly to moderately expressed this molecule. From day 10 to 15 of gestation, no embigin signal was detected. Basigin was more broadly expressed. During the organogenesis period, basigin was expressed in various epithelial tissues, brain ventricles, the spinal cord and dorsal root ganglion. The modes of expression of these two proteins throughout the egg cylinder stage correlated with the expression of the carbohydrate markers that they carry; embigin with Dolichos biflorus agglutinin binding sites and basigin with Le^x antigen and more closely with fucosyltransferase IV, which forms the antigenic epitope. These findings imply that proteins with specific carbohydrate epitopes play roles in early postimplantation embryogenesis.     

A proposed CO2-controlled mechanism of woody plant invasion in grasslands and savannas

We propose that elevated CO₂ may have a significant positive effect on woody plant success and thus favour tree invasion and thickening in grass‐dominated ecosystems. We note that savanna tree biomass is strongly constrained by disturbance, particularly fire, and that elevated CO₂ could act to reduce this constraint. Our argument combines knowledge of tree recovery from injury after grassland fires, with theory about carbon acquisition and carbohydrate storage patterns in C3 woody plants in response to elevated CO₂. We propose simply that elevated CO₂ will tend to favour regrowth of juvenile trees trapped (sometimes for decades) in the ‘topkill’ zone, thus allowing them to escape more readily from periodic fires as CO₂ continues to rise. Little empirical evidence exists to test this hypothesis, even though the process may have important implications for tree/grass codominated ecosystems currently in a dynamic equilibrium.