Lectins: Proteins that share the common characteristic of binding to carbohydrates. Some ANTIBODIES and carbohydrate-metabolizing proteins (ENZYMES) also bind to carbohydrates, however they are not considered lectins. PLANT LECTINS are carbohydrate-binding proteins that have been primarily identified by their hemagglutinating activity (HEMAGGLUTININS). However, a variety of lectins occur in animal species where they serve diverse array of functions through specific carbohydrate recognition.Plant Lectins: Protein or glycoprotein substances of plant origin that bind to sugar moieties in cell walls or membranes. Some carbohydrate-metabolizing proteins (ENZYMES) from PLANTS also bind to carbohydrates, however they are not considered lectins. Many plant lectins change the physiology of the membrane of BLOOD CELLS to cause agglutination, mitosis, or other biochemical changes. They may play a role in plant defense mechanisms.Mannose-Binding Lectins: A subclass of lectins that are specific for CARBOHYDRATES that contain MANNOSE.Wheat Germ Agglutinins: Lectins purified from the germinating seeds of common wheat (Triticum vulgare); these bind to certain carbohydrate moieties on cell surface glycoproteins and are used to identify certain cell populations and inhibit or promote some immunological or physiological activities. There are at least two isoforms of this lectin.Lectins, C-Type: A class of animal lectins that bind to carbohydrate in a calcium-dependent manner. They share a common carbohydrate-binding domain that is structurally distinct from other classes of lectins.Galectins: A class of animal lectins that bind specifically to beta-galactoside in a calcium-independent manner. Members of this class are distiguished from other lectins by the presence of a conserved carbohydrate recognition domain. The majority of proteins in this class bind to sugar molecules in a sulfhydryl-dependent manner and are often referred to as S-type lectins, however this property is not required for membership in this class.Glycoconjugates: Carbohydrates covalently linked to a nonsugar moiety (lipids or proteins). The major glycoconjugates are glycoproteins, glycopeptides, peptidoglycans, glycolipids, and lipopolysaccharides. (From Biochemical Nomenclature and Related Documents, 2d ed; From Principles of Biochemistry, 2d ed)Peanut Agglutinin: Lectin purified from peanuts (ARACHIS HYPOGAEA). It binds to poorly differentiated cells and terminally differentiated cells and is used in cell separation techniques.Carbohydrates: The largest class of organic compounds, including STARCH; GLYCOGEN; CELLULOSE; POLYSACCHARIDES; and simple MONOSACCHARIDES. Carbohydrates are composed of carbon, hydrogen, and oxygen in a ratio of Cn(H2O)n.Concanavalin A: A MANNOSE/GLUCOSE binding lectin isolated from the jack bean (Canavalia ensiformis). It is a potent mitogen used to stimulate cell proliferation in lymphocytes, primarily T-lymphocyte, cultures.Galactosides: Glycosides formed by the reaction of the hydroxyl group on the anomeric carbon atom of galactose with an alcohol to form an acetal. They include both alpha- and beta-galactosides.Galanthus: A plant genus in the family LILIACEAE (sometimes classified as Amaryllidaceae). Galanthus nivalis L. is the source of GALANTHAMINE.Acetylgalactosamine: The N-acetyl derivative of galactosamine.Fetuins: A family of calcium-binding alpha-globulins that are synthesized in the LIVER and play an essential role in maintaining the solubility of CALCIUM in the BLOOD. In addition the fetuins contain aminoterminal cystatin domains and are classified as type 3 cystatins.Receptors, Mitogen: Glycoprotein molecules on the surface of B- and T-lymphocytes, that react with molecules of antilymphocyte sera, lectins, and other agents which induce blast transformation of lymphocytes.Hemagglutination: The aggregation of ERYTHROCYTES by AGGLUTININS, including antibodies, lectins, and viral proteins (HEMAGGLUTINATION, VIRAL).Carbohydrate Metabolism: Cellular processes in biosynthesis (anabolism) and degradation (catabolism) of CARBOHYDRATES.Agglutination: The clumping together of suspended material resulting from the action of AGGLUTININS.Mannose: A hexose or fermentable monosaccharide and isomer of glucose from manna, the ash Fraxinus ornus and related plants. (From Grant & Hackh's Chemical Dictionary, 5th ed & Random House Unabridged Dictionary, 2d ed)Carbohydrate Sequence: The sequence of carbohydrates within POLYSACCHARIDES; GLYCOPROTEINS; and GLYCOLIPIDS.Canavalia: A plant genus of the family FABACEAE. Canavalia ensiformis is the source of CONCANAVALIN A.Artocarpus: A plant genus of the family MORACEAE. Puag-haad extract, from A. lakoocha, contains STILBENES and related 4-substituted RESORCINOLS.Ricinus: A plant genus of the family EUPHORBIACEAE, order Euphorbiales, subclass Rosidae. The seed of Ricinus communis L. is the CASTOR BEAN which is the source of CASTOR OIL; RICIN; and other lectins.PolysaccharidesGalactose: An aldohexose that occurs naturally in the D-form in lactose, cerebrosides, gangliosides, and mucoproteins. Deficiency of galactosyl-1-phosphate uridyltransferase (GALACTOSE-1-PHOSPHATE URIDYL-TRANSFERASE DEFICIENCY DISEASE) causes an error in galactose metabolism called GALACTOSEMIA, resulting in elevations of galactose in the blood.Ribosome Inactivating Proteins, Type 2: Ribosome inactivating proteins consisting of two polypeptide chains, the toxic A subunit and a lectin B subunit, linked by disulfide bridges. The lectin portion binds to cell surfaces and facilitates transport into the ENDOPLASMIC RETICULUM.Hemagglutinins: Agents that cause agglutination of red blood cells. They include antibodies, blood group antigens, lectins, autoimmune factors, bacterial, viral, or parasitic blood agglutinins, etc.Agglutinins: Substances, usually of biological origin, that cause cells or other organic particles to aggregate and stick to each other. They include those ANTIBODIES which cause aggregation or agglutination of particulate or insoluble ANTIGENS.Hemagglutination Tests: Sensitive tests to measure certain antigens, antibodies, or viruses, using their ability to agglutinate certain erythrocytes. (From Stedman, 26th ed)FucoseAsialoglycoproteins: Endogenous glycoproteins from which SIALIC ACID has been removed by the action of sialidases. They bind tightly to the ASIALOGLYCOPROTEIN RECEPTOR which is located on hepatocyte plasma membranes. After internalization by adsorptive ENDOCYTOSIS they are delivered to LYSOSOMES for degradation. Therefore receptor-mediated clearance of asialoglycoproteins is an important aspect of the turnover of plasma glycoproteins. They are elevated in serum of patients with HEPATIC CIRRHOSIS or HEPATITIS.Mannosides: Glycosides formed by the reaction of the hydroxyl group on the anomeric carbon atom of mannose with an alcohol to form an acetal. They include both alpha- and beta-mannosides.Glycoproteins: Conjugated protein-carbohydrate compounds including mucins, mucoid, and amyloid glycoproteins.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Acetylglucosamine: The N-acetyl derivative of glucosamine.Mistletoe: Parasitic plants that form a bushy growth on branches of host trees which are in the order Santalales. It includes the Christmas mistletoe family (VISCACEAE), the showy mistletoe family (LORANTHACEAE) and the catkin mistletoe family (Eremolepidaceae). The composition of toxins, lectins, tyramine, phenethylamines, and other compounds may be affected by the host.Chromatography, Affinity: A chromatographic technique that utilizes the ability of biological molecules to bind to certain ligands specifically and reversibly. It is used in protein biochemistry. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Ribosome Inactivating Proteins: N-Glycosidases that remove adenines from RIBOSOMAL RNA, depurinating the conserved alpha-sarcin loop of 28S RIBOSOMAL RNA. They often consist of a toxic A subunit and a binding lectin B subunit. They may be considered as PROTEIN SYNTHESIS INHIBITORS. They are found in many PLANTS and have cytotoxic and antiviral activity.Plants, Medicinal: Plants whose roots, leaves, seeds, bark, or other constituent parts possess therapeutic, tonic, purgative, curative or other pharmacologic attributes, when administered to man or animals.Oligosaccharides: Carbohydrates consisting of between two (DISACCHARIDES) and ten MONOSACCHARIDES connected by either an alpha- or beta-glycosidic link. They are found throughout nature in both the free and bound form.Fabaceae: The large family of plants characterized by pods. Some are edible and some cause LATHYRISM or FAVISM and other forms of poisoning. Other species yield useful materials like gums from ACACIA and various LECTINS like PHYTOHEMAGGLUTININS from PHASEOLUS. Many of them harbor NITROGEN FIXATION bacteria on their roots. Many but not all species of "beans" belong to this family.N-Acetylneuraminic Acid: An N-acyl derivative of neuraminic acid. N-acetylneuraminic acid occurs in many polysaccharides, glycoproteins, and glycolipids in animals and bacteria. (From Dorland, 28th ed, p1518)Receptors, N-Acetylglucosamine: Cell surface receptors that bind to ACETYLGLUCOSAMINE.Glycosylation: The chemical or biochemical addition of carbohydrate or glycosyl groups to other chemicals, especially peptides or proteins. Glycosyl transferases are used in this biochemical reaction.Methylmannosides: Mannosides formed by the reaction of the hydroxyl group on the anomeric carbon atom of mannose with methyl alcohol. They include both alpha- and beta-methylmannosides.Abrin: A toxic lectin from the seeds of jequirity, Abrus precatorius L. Very active poison. Five different proteins have so far been isolated: Abrus agglutinin, the component responsible for: hemagglutinating activity, & abrins a-d, the toxic principals each consisting of two peptide chains are held together by disulfide bonds.Phytohemagglutinins: Mucoproteins isolated from the kidney bean (Phaseolus vulgaris); some of them are mitogenic to lymphocytes, others agglutinate all or certain types of erythrocytes or lymphocytes. They are used mainly in the study of immune mechanisms and in cell culture.Amino Acid Sequence: The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.Monosaccharides: Simple sugars, carbohydrates which cannot be decomposed by hydrolysis. They are colorless crystalline substances with a sweet taste and have the same general formula CnH2nOn. (From Dorland, 28th ed)Erythrina: A genus of leguminous shrubs or trees, mainly tropical, yielding useful compounds such as ALKALOIDS and PLANT LECTINS.Galectin 1: A galectin found abundantly in smooth muscle (MUSCLE, SMOOTH) and SKELETAL MUSCLE and many other tissues. It occurs as a homodimer with two 14-kDa subunits.Histocytochemistry: Study of intracellular distribution of chemicals, reaction sites, enzymes, etc., by means of staining reactions, radioactive isotope uptake, selective metal distribution in electron microscopy, or other methods.Sambucus: A plant genus in the family CAPRIFOLIACEAE known for elderberries.Protein Binding: The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.Sialic Acids: A group of naturally occurring N-and O-acyl derivatives of the deoxyamino sugar neuraminic acid. They are ubiquitously distributed in many tissues.Binding Sites: The parts of a macromolecule that directly participate in its specific combination with another molecule.Receptors, Concanavalin A: Glycoprotein moieties on the surfaces of cell membranes that bind concanavalin A selectively; the number and location of the sites depends on the type and condition of the cell.Galectin 3: A multifunctional galactin initially discovered as a macrophage antigen that binds to IMMUNOGLOBULIN E, and as 29-35-kDa lectin that binds LAMININ. It is involved in a variety of biological events including interactions with galactose-containing glycoconjugates, cell proliferation, CELL DIFFERENTIATION, and APOPTOSIS.Electrophoresis, Polyacrylamide Gel: Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.Carbohydrate Conformation: The characteristic 3-dimensional shape of a carbohydrate.Agglutination Tests: Tests that are dependent on the clumping of cells, microorganisms, or particles when mixed with specific antiserum. (From Stedman, 26th ed)Glycosides: Any compound that contains a constituent sugar, in which the hydroxyl group attached to the first carbon is substituted by an alcoholic, phenolic, or other group. They are named specifically for the sugar contained, such as glucoside (glucose), pentoside (pentose), fructoside (fructose), etc. Upon hydrolysis, a sugar and nonsugar component (aglycone) are formed. (From Dorland, 28th ed; From Miall's Dictionary of Chemistry, 5th ed)Collectins: A class of C-type lectins that target the carbohydrate structures found on invading pathogens. Binding of collectins to microorganisms results in their agglutination and enhanced clearance. Collectins form trimers that may assemble into larger oligomers. Each collectin polypeptide chain consists of four regions: a relatively short N-terminal region, a collagen-like region, an alpha-helical coiled-coil region, and carbohydrate-binding region.Galectin 4: A galectin found in the small and large intestine and the stomach. It occurs as a homodimer with two 36-kDa subunits and is localized to sites of cell adhesion where it may play role in assembly of ADHERENS JUNCTIONS.Castor Bean: Common name for Ricinus communis, a species in the family EUPHORBIACEAE. It is the source of CASTOR OIL.Aralia: A plant genus in the family ARALIACEAE, order Apiales, subclass Rosidae. It includes Aralia californica S. Watson, Aralia nudicaulis L., and Aralia racemosa L.Sea Cucumbers: A class of Echinodermata characterized by long, slender bodies.Neuraminidase: An enzyme that catalyzes the hydrolysis of alpha-2,3, alpha-2,6-, and alpha-2,8-glycosidic linkages (at a decreasing rate, respectively) of terminal sialic residues in oligosaccharides, glycoproteins, glycolipids, colominic acid, and synthetic substrate. (From Enzyme Nomenclature, 1992)Lactose: A disaccharide of GLUCOSE and GALACTOSE in human and cow milk. It is used in pharmacy for tablets, in medicine as a nutrient, and in industry.Datura stramonium: A plant species of the genus DATURA, family SOLANACEAE, that contains TROPANES and other SOLANACEOUS ALKALOIDS.Ricin: A protein phytotoxin from the seeds of Ricinus communis, the castor oil plant. It agglutinates cells, is proteolytic, and causes lethal inflammation and hemorrhage if taken internally.Liliaceae: A monocot family within the order Liliales. This family is divided by some botanists into other families such as Convallariaceae, Hyacinthaceae and Amaryllidaceae. Amaryllidaceae, which have inferior ovaries, includes CRINUM; GALANTHUS; LYCORIS; and NARCISSUS and are known for AMARYLLIDACEAE ALKALOIDS.Musa: A plant genus of the family Musaceae, order Zingiberales, subclass Zingiberidae, class Liliopsida.Seeds: The encapsulated embryos of flowering plants. They are used as is or for animal feed because of the high content of concentrated nutrients like starches, proteins, and fats. Rapeseed, cottonseed, and sunflower seed are also produced for the oils (fats) they yield.Soybean Proteins: Proteins which are present in or isolated from SOYBEANS.Glycopeptides: Proteins which contain carbohydrate groups attached covalently to the polypeptide chain. The protein moiety is the predominant group with the carbohydrate making up only a small percentage of the total weight.Arachis hypogaea: A plant species of the family FABACEAE that yields edible seeds, the familiar peanuts, which contain protein, oil and lectins.ABO Blood-Group System: The major human blood type system which depends on the presence or absence of two antigens A and B. Type O occurs when neither A nor B is present and AB when both are present. A and B are genetic factors that determine the presence of enzymes for the synthesis of certain glycoproteins mainly in the red cell membrane.Molecular Weight: The sum of the weight of all the atoms in a molecule.Bauhinia: A plant genus of the family FABACEAE. Members contain isoacteoside, luteolin, indole-3-carboxylic acid.Horseshoe Crabs: An arthropod subclass (Xiphosura) comprising the North American (Limulus) and Asiatic (Tachypleus) genera of horseshoe crabs.Plants: Multicellular, eukaryotic life forms of kingdom Plantae (sensu lato), comprising the VIRIDIPLANTAE; RHODOPHYTA; and GLAUCOPHYTA; all of which acquired chloroplasts by direct endosymbiosis of CYANOBACTERIA. They are characterized by a mainly photosynthetic mode of nutrition; essentially unlimited growth at localized regions of cell divisions (MERISTEMS); cellulose within cells providing rigidity; the absence of organs of locomotion; absence of nervous and sensory systems; and an alternation of haploid and diploid generations.Toxins, Biological: Specific, characterizable, poisonous chemicals, often PROTEINS, with specific biological properties, including immunogenicity, produced by microbes, higher plants (PLANTS, TOXIC), or ANIMALS.alpha-Fetoproteins: The first alpha-globulins to appear in mammalian sera during FETAL DEVELOPMENT and the dominant serum proteins in early embryonic life.Mannose-Binding Lectin: A specific mannose-binding member of the collectin family of lectins. It binds to carbohydrate groups on invading pathogens and plays a key role in the MANNOSE-BINDING LECTIN COMPLEMENT PATHWAY.Glycomics: The systematic study of the structure and function of the complete set of glycans (the glycome) produced in a single organism and identification of all the genes that encode glycoproteins.Sequence Homology, Amino Acid: The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.Amino Sugars: SUGARS containing an amino group. GLYCOSYLATION of other compounds with these amino sugars results in AMINOGLYCOSIDES.