Biomaterial Database

Sequence of a cysteine-rich galactose-specific lectin of Entamoeba histolytica. 1991

B J Mann, and B E Torian, and T S Vedvick, and W A Petri

Department of Medicine, University of Virginia, Charlottesville 22908.

Entamoeba histolytica trophozoites adhere to human colonic mucins and epithelial cells by a cell surface galactose-specific lectin. This lectin, which is composed of two subunits linked by disulfide bonds, has been shown to be a protective antigen in an animal model of amebiasis. We have determined the sequence of the mature form of the 170-kDa heavy subunit from cDNA clones and PCR-amplified fragments. The heavy subunit sequence consisted of a putative extracellular domain containing 1209 amino acids with 16 potential sites for N-linked glycosylation, a 26-amino acid hydrophobic region, and a 41-amino acid cytoplasmic tail. The presence of N-linked oligosaccharides was confirmed by culturing amebae with tunicamycin, which resulted in a decrease in the heavy subunit molecular mass to 160 kDa and a loss of lectin activity. The extracellular domain was remarkable for an extensive cysteine-rich domain that shared identify with similar regions of several other cell surface proteins and appeared to confer protease resistance to the subunit.

UI	MeSH Term	Description	Entries
D008969	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.	Sequence Data, Molecular,Molecular Sequencing Data,Data, Molecular Sequence,Data, Molecular Sequencing,Sequencing Data, Molecular
D008970	Molecular Weight	The sum of the weight of all the atoms in a molecule.	Molecular Weights,Weight, Molecular,Weights, Molecular
D010084	Oxidation-Reduction	A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).	Redox,Oxidation Reduction
D010450	Endopeptidases	A subclass of PEPTIDE HYDROLASES that catalyze the internal cleavage of PEPTIDES or PROTEINS.	Endopeptidase,Peptide Peptidohydrolases
D003001	Cloning, Molecular	The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.	Molecular Cloning
D003545	Cysteine	A thiol-containing non-essential amino acid that is oxidized to form CYSTINE.	Cysteine Hydrochloride,Half-Cystine,L-Cysteine,Zinc Cysteinate,Half Cystine,L Cysteine
D004748	Entamoeba histolytica	A species of parasitic protozoa causing ENTAMOEBIASIS and amebic dysentery (DYSENTERY, AMEBIC). Characteristics include a single nucleus containing a small central karyosome and peripheral chromatin that is finely and regularly beaded.	Endamoeba histolytica,histolytica, Endamoeba
D005690	Galactose	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.	D-Galactose,Galactopyranose,Galactopyranoside,D Galactose
D006031	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).	Protein Glycosylation,Glycosylation, Protein
D000478	Alkylation	The covalent bonding of an alkyl group to an organic compound. It can occur by a simple addition reaction or by substitution of another functional group.	Alkylations