Biomaterial Database

Proton nuclear magnetic resonance studies of soybean lectin-monosaccharide interactions: computer analysis of complex binding behavior. 1986

C Preston, and J M Preston

1H NMR was used to quantify soybean lectin binding to monosaccharides, using presaturation of HOD plus a spin-echo sequence to observe sugar -NHCOCH3 and -OCH3 to below 0.01 mM. Binding is in the very-slow-exchange limit; there is no broadening or shifting and only unbound sugar is observed for pH 5 to 8 and 25 to 75 degrees C. Preliminary results were consistent with those previously reported for methyl 2-acetamido-2-deoxy-alpha-D-galactopyranoside (Me alpha-D-GalNAcp) (K = 3 X 10(4) liters mol-1 with four sites per tetramer). More detailed studies, however, gave concave Scatchard plots for methyl 2-acetamido-2-deoxy-alpha- and beta-D-galactopyranoside, (Me alpha- and Me beta-D-GalNAcp), best fitted using K1 values of (6-12) X 10(4) liters mol-1, K2 values less than or equal to 0.5 X 10(4) liters mol-1, and four sites of each type in D2O or 80% H2O at 25 degrees C and pH 7.2. Data for methyl alpha-D-galactopyranoside were fitted with K = 0.5 X 10(4) liters mol-1 and eight sites of the same K. Monosaccharides may be binding in the recently reported "hydrophobic sites" of soybean lectin. Both methyl 2-acetamido-2-deoxy-beta-D-galactofuranoside (Me beta-D-GalNAcf) and methyl 2-acetamido-2-deoxy-alpha-D-glucopyranoside (Me alpha-D-GlcNAcP) showed some binding by 1H NMR; K's were similar to those for the high-affinity sugars, but the occupancy was much lower. The soybean lectin in this study was saturated in Ca2+ (greater than or equal to 4 mol/tetramer), but low in Mn2+, with Mn2+ plus Mg2+ less than 4. We report new melting points for D-N-acetylgalactosamine, Me alpha-D-GlcNAcp, Me beta-D-GalNAcp, and Me beta-D-GalNAcf, and a fully listed program for fitting curved Scatchard plots using Apple IIc and IIe computers.

UI	MeSH Term	Description	Entries
D009005	Monosaccharides	Single chain carbohydrates that are the most basic units of CARBOHYDRATES. They are typically colorless crystalline substances with a sweet taste and have the same general formula CnH2nOn.	Monosaccharide,Simple Sugar,Simple Sugars,Sugar, Simple,Sugars, Simple
D009682	Magnetic Resonance Spectroscopy	Spectroscopic method of measuring the magnetic moment of elementary particles such as atomic nuclei, protons or electrons. It is employed in clinical applications such as NMR Tomography (MAGNETIC RESONANCE IMAGING).	In Vivo NMR Spectroscopy,MR Spectroscopy,Magnetic Resonance,NMR Spectroscopy,NMR Spectroscopy, In Vivo,Nuclear Magnetic Resonance,Spectroscopy, Magnetic Resonance,Spectroscopy, NMR,Spectroscopy, Nuclear Magnetic Resonance,Magnetic Resonance Spectroscopies,Magnetic Resonance, Nuclear,NMR Spectroscopies,Resonance Spectroscopy, Magnetic,Resonance, Magnetic,Resonance, Nuclear Magnetic,Spectroscopies, NMR,Spectroscopy, MR
D011485	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.	Plasma Protein Binding Capacity,Binding, Protein
D011522	Protons	Stable elementary particles having the smallest known positive charge, found in the nuclei of all elements. The proton mass is less than that of a neutron. A proton is the nucleus of the light hydrogen atom, i.e., the hydrogen ion.	Hydrogen Ions,Hydrogen Ion,Ion, Hydrogen,Ions, Hydrogen,Proton
D003201	Computers	Programmable electronic devices designed to accept data, perform prescribed mathematical and logical operations at high speed, and display the results of these operations.	Calculators, Programmable,Computer Hardware,Computers, Digital,Hardware, Computer,Calculator, Programmable,Computer,Computer, Digital,Digital Computer,Digital Computers,Programmable Calculator,Programmable Calculators
D006385	Hemagglutination Inhibition Tests	Serologic tests in which a known quantity of antigen is added to the serum prior to the addition of a red cell suspension. Reaction result is expressed as the smallest amount of antigen which causes complete inhibition of hemagglutination.	Hemagglutination Inhibition Test,Inhibition Test, Hemagglutination,Inhibition Tests, Hemagglutination,Test, Hemagglutination Inhibition,Tests, Hemagglutination Inhibition
D006863	Hydrogen-Ion Concentration	The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH	pH,Concentration, Hydrogen-Ion,Concentrations, Hydrogen-Ion,Hydrogen Ion Concentration,Hydrogen-Ion Concentrations
D013696	Temperature	The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.	Temperatures
D030262	Soybean Proteins	Proteins which are present in or isolated from SOYBEANS.	Dietary Soybean Protein,Soy Bean Protein,Soybean Protein,Dietary Soybean Proteins,Soy Bean Proteins,Soy Protein,Soy Proteins,Bean Protein, Soy,Protein, Dietary Soybean,Protein, Soy,Protein, Soy Bean,Protein, Soybean,Proteins, Dietary Soybean,Proteins, Soy,Soybean Protein, Dietary,Soybean Proteins, Dietary
D037102	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.	Animal Lectin,Animal Lectins,Isolectins,Lectin,Isolectin,Lectin, Animal,Lectins, Animal