Heterogeneity-Bovine-Corneal-Proteokeratan-Sulfate-v

Proteokeratan sulfate was extracted and purified from bovine corneal stroma and then characterized by chemical and biochemical analyses. It was fractionated into several fractions by affinity chromatography on a concanavalin A-Sepharose column or by hydrophobic chromatography on a phenyl-Sepharose column. These fractions differed widely from one another in carbohydrate content, though no significant differences of their amino acid compositions were observed. One fraction (ca. 25%, on a dry weight basis) tightly bound to a concanavalin A-Sepharose column, compared with another fraction (ca. 65%) weakly bound to the same column, was poor in galactose and N-acetylglucosamine, but contained mannose in a high proportion.

Fractions (ca. %) tightly bound to a phenyl-Sepharose column, in contrast to the one (ca. 66%) weakly bound, had low carbohydrate contents, like the fraction tightly bound to a concanavalin A-Sepharose column. Additionally, the fractions tightly bound to these affinity columns exhibited strong inhibitory actions on erythrocyte-concanavalin A agglutination. To obtain further details of the carbohydrate moiety of the proteokeratan sulfate, an attempt was made to separate and characterize peptidokeratan sulfate and Asn-linked oligosaccharide derived from some proteokeratan sulfate fractions. The present work revealed that the proteokeratan sulfate contains keratan sulfate and high mannose-type oligosaccharide in an approximate chain number ratio of 31, the keratan sulfate content varies widely and the oligosaccharide content increases with decrease of the keratan sulfate content, and the protein core is homogeneous at least with respect to the amino acid composition.DOI 3oxfordjournals.

jbchem.a121931An overview on biological production of functional lactose derivatives.Lactose is a natural disaccharide obtained from the milk of most mammals and a waste product of cheese and casein manufacturing. Over the past decades, lactose in whey has increasingly been promoted as an important resource, and an increasing number of significant advances have been made to investigate its healthy and functional properties. Lactose can be biotransformed into many kinds of derivatives, including galacto-oligosaccharides, epilactose, lactulose, lactosucrose, and D-tagatose. Biological efficiency and safety are critical for the enzymatic production of lactose derivatives from lactose. These lactose derivatives show a range of prominent physiological features and effects, such as prebiotic properties, indigestibility, and obesity prevention, which can be utilized in the pharmaceutical, health, and food industries.

In 2'-FL , we present the properties and physiological effects of lactose derivatives, detailing their biological production by various enzymes and their applications in dairy products, especially directly in the milk industry.STAT a saccharide topology analysis tool used in combination with tandem mass Sequential stages of mass spectrometry (MSn) have the potential to provide a great deal of structural information in glycan analysis. The saccharide topology analysis tool (STAT) presented here is a Web-based computational program that can quickly extract sequence information from a set of MSn spectra for an oligosaccharide of up to residues. After information such as precursor ion mass, possible monosaccharide moieties, charge carrier, and product ion mass has been input, all possible connectivities are generated and evaluated against the MSn data. The list of possible structures is given a rating based on the likelihood that it is the correct sequence. Examples are given to demonstrate the feasibility of applying STAT to MSn data generated from bacterial lipooligosaccharides and an N-linked glycan. The major advantage of STAT is that the list of possible structures is generated quickly and the rating system pushes the more likely structures to the top of the list.

Combining 2'-FL generated by STAT with data on the branching patterns of the glycan serves to eliminate all but a handful of structures. These remaining structures could then be used to guide further structural analysis.Structure of human transferrin receptor oligosaccharides conservation of The human transferrin receptor (TfR) has three N-linked oligosaccharides. A combination of site-directed mutagenesis and carbohydrate and protein chemistry was used to characterize the structures of the N-linked oligosaccharides and to map their locations. We find that the type of oligosaccharide at each position was unique for that particular site. Human TfR isolated from placentae was used to characterize the structure of the oligosaccharides found in the native TfR.