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Glycoproteins
Conjugated protein-carbohydrate compounds including MUCINS; mucoid, and AMYLOID glycoproteins.
Hemagglutinin Glycoproteins, Influenza Virus
Membrane glycoproteins from influenza viruses which are involved in hemagglutination, virus attachment, and envelope fusion. Fourteen distinct subtypes of HA glycoproteins and nine of NA glycoproteins have been identified from INFLUENZA A VIRUS; no subtypes have been identified for Influenza B or Influenza C viruses.
Year introduced: 1997
Variant Surface Glycoproteins, Trypanosoma
Glycoproteins attached to the surface coat of the trypanosome. Many of these glycoproteins show amino acid sequence diversity expressed as antigenic variations. This continuous development of antigenically distinct variants in the course of infection ensures that some trypanosomes always survive the development of immune response to propagate the infection.
Year introduced: 1988
Pregnancy-Specific beta 1-Glycoproteins
Glycoproteins with the electrophoretic mobility of BETA-GLOBULINS, secreted by the placental TROPHOBLASTS into the maternal bloodstream during PREGNANCY. They can be detected 18 days after OVULATION and reach 200 mg/ml at the end of pregnancy. They are associated with fetal well-being.
Year introduced: 2005(1980)
Platelet Membrane Glycoproteins
Surface glycoproteins on platelets which have a key role in hemostasis and thrombosis such as platelet adhesion and aggregation. Many of these are receptors.
Year introduced: 1987
Membrane Glycoproteins
Glycoproteins found on the membrane or surface of cells.
Zona Pellucida Glycoproteins
Membrane glycoproteins that constitute the ZONA PELLUCIDA in mammals and function in the recognition and binding of SPERMATOZOA.
Year introduced: 2017 (1981)
Lysosomal Membrane Proteins
Ubiquitously expressed integral membrane glycoproteins found in the LYSOSOME.
Year introduced: 2006(1986)
Asialoglycoproteins
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.
Year introduced: 1985
Pregnancy-Associated alpha 2-Macroglobulins
Large (>160 kDa) glycoproteins with electrophoretic mobility of ALPHA-GLOBULINS, found in high concentration in the plasma of pregnant women but also in a number of species including mouse, rat, and others (ALPHA-MACROGLOBULINS). In humans, they are always present in the circulation and are nonspecific inhibitors of PROTEINASES, similar to COMPLEMENT PROTEINS (C3; C4; C5).
Year introduced: 2018 (2004)
Viral Fusion Proteins
Proteins, usually glycoproteins, found in the viral envelopes of a variety of viruses. They promote cell membrane fusion and thereby may function in the uptake of the virus by cells.
Acute-Phase Proteins
Proteins that are secreted into the blood in increased or decreased quantities by hepatocytes in response to trauma, inflammation, or disease. These proteins can serve as inhibitors or mediators of the inflammatory processes. Certain acute-phase proteins have been used to diagnose and follow the course of diseases or as tumor markers.
Antifreeze Proteins
Proteins that bind to ice and modify the growth of ice crystals. They perform a cryoprotective role in a variety of organisms.
Year introduced: 2001
ATP Binding Cassette Transporter, Subfamily B
A subfamily of transmembrane proteins from the superfamily of ATP-BINDING CASSETTE TRANSPORTERS that are closely related in sequence to ATP BINDING CASSETTE TRANSPORTER, SUBFAMILY B, MEMBER 1. When overexpressed, they function as ATP-dependent efflux pumps able to extrude lipophilic drugs (especially ANTINEOPLASTIC AGENTS) from cells, causing multidrug resistance (DRUG RESISTANCE, MULTIPLE). Although ATP BINDING CASSETTE TRANSPORTER, SUBFAMILY B share functional similarities to MULTIDRUG RESISTANCE-ASSOCIATED PROTEINS they are two distinct subclasses of ATP-BINDING CASSETTE TRANSPORTERS, and have little sequence homology.
Year introduced: 2019 (1999)
Integrins
A family of transmembrane glycoproteins (MEMBRANE GLYCOPROTEINS) consisting of noncovalent heterodimers. They interact with a wide variety of ligands including EXTRACELLULAR MATRIX PROTEINS; COMPLEMENT, and other cells, while their intracellular domains interact with the CYTOSKELETON. The integrins consist of at least three identified families: the cytoadhesin receptors (RECEPTORS, CYTOADHESIN), the leukocyte adhesion receptors (RECEPTORS, LEUKOCYTE ADHESION), and the VERY LATE ANTIGEN RECEPTORS. Each family contains a common beta-subunit (INTEGRIN BETA CHAINS) combined with one or more distinct alpha-subunits (INTEGRIN ALPHA CHAINS). These receptors participate in cell-matrix and cell-cell adhesion in many physiologically important processes, including embryological development; HEMOSTASIS; THROMBOSIS; WOUND HEALING; immune and nonimmune defense mechanisms; and oncogenic transformation.
Year introduced: 1990
Viral Envelope Proteins
Integral membrane proteins that are incorporated into the VIRAL ENVELOPE. They are glycosylated during VIRAL ASSEMBLY.
Year introduced: 1984
Glycosylation
The synthetic chemistry reaction or enzymatic reaction of adding carbohydrate or glycosyl groups. GLYCOSYLTRANSFERASES carry out the enzymatic glycosylation reactions. The spontaneous, non-enzymatic attachment of reducing sugars to free amino groups in proteins, lipids, or nucleic acids is called GLYCATION (see MAILLARD REACTION).
Follistatin-Related Proteins
Broadly distributed glycoproteins that are homologous to the activin-binding protein, FOLLISTATIN. These follistatin-related proteins are encoded by a number of genes.
Year introduced: 2003
Thrombospondins
A family of related, adhesive glycoproteins which are synthesized, secreted, and incorporated into the extracellular matrix of a variety of cells, including alpha granules of platelets following thrombin activation and endothelial cells. They interact with a number of BLOOD COAGULATION FACTORS and anticoagulant factors. Five distinct forms have been identified, thrombospondin 1, -2, -3, -4, and cartilage oligomeric matrix protein (COMP). They are involved in cell adhesion, platelet aggregation, cell proliferation, angiogenesis, tumor metastasis, VASCULAR SMOOTH MUSCLE growth, and tissue repair.
Year introduced: 1998
Glycocalyx
The carbohydrate-rich zone on the cell surface. This zone can be visualized by a variety of stains as well as by its affinity for lectins. Although most of the carbohydrate is attached to intrinsic plasma membrane molecules, the glycocalyx usually also contains both glycoproteins and proteoglycans that have been secreted into the extracellular space and then adsorbed onto the cell surface. (Alberts et al., Molecular Biology of the Cell, 3d ed, p502)