Disaccharides, carbohydrates, and their derivatives - PDF

Disaccharides Scan ppts for protecting alignment of normal ppts Important Important Starch Linear D-glucose units (also called as Amylose) When it contains When it Branches with D-Glucose linear unit, Called as Starch (branched portion calls as Amylo Cellulases are enzymes present...

Disaccharides Scan ppts for protecting alignment of normal ppts Important Important Starch Linear D-glucose units (also called as Amylose) When it contains When it Branches with D-Glucose linear unit, Called as Starch (branched portion calls as Amylo Cellulases are enzymes present in bacteria and animals. END OF HOMO-POLYSACCHRIDES  END Normal Ppts below  (These are also called as mucopolysaccharides) But are not polysaccharides & disaccharides. Are Carbohydrate derivatives GAGs are divided again into : (1) Non-sulfated GAGs (But are Amino sugar & Sugar acids and derivatives (Example: Hyaluronic acid (HA) (2) Sulfated GAGs (Example: ) Example of GAG’s: Hyaluronic acid (is a naturally occurring bio- polysaccharide) Polymer composed of D-glucuronic acid and N-acetyl-D-glucosamine disaccharide units, Linked via alternating β-(1→4) and β-(1→3) glycosidic bonds. Hyaluronic acid can be 25,000 disaccharide repeats in length Found in organisms from bacteria to animals, including humans Found in connective tissues, synovial fluid, the vitreous fluid of the eye, umbilical cords and chicken combs & required for wound repair Integral membrane proteins called hyaluronan synthases synthesize HA Hyaluronic HA is degraded by a family of acid enzymes called hyaluronidases. HA has a stiff viscous quality like gel glycosidic bond 5 5 4 1 1 Figures showing β OR α 3 configuration of linkage. β-(1→4) β-(1→4) GAGs: differ in hexosamine, β-(1→3) hexose or hexuronic unit types and glycosidic bond type C2: aminated with –NH2 gp -NH further linked to acetyl group (-COCH3)  Somemore functions of HA: Biological functions include maintenance of elastoviscosity of liquid connective tissues such as synovial and eye vitreous fluid control of tissue hydration and water transport supramolecular assembly of proteoglycans in the extracellular matrix and various receptor-mediated roles in cell detachment, mitosis, migration, tumor development and metastasis and inflammation By binding water in the body, HA lubricates movable parts like joints and muscles HA is a signalling molecule involved in mammalian biological processes and plays roles in disease causing events such as inflammation, tumorigenesis and abnormal immune function Bacteria such as Streptococcus zoo-epidemicus synthesise HA and use it to encapsulate their cells and escape detection from the host’s immune system Glycosaminoglycans further classified into Glucuronic acid + N-acetyl-Galactosamine sulfate Direction of the disaccharide unit Sulfonic gp β β 4 1 glycosidic 3 2 bond C2: aminated with –NH2 gp -NH further linked to acetyl group (-COCH3)  Sulfonic gp β 1 3 α glycosidic bond L-Iduronic acid + N-acetyl- Galactosamine sulfate β β 1 4 glycosidic bond  6 β 4 1 2 D-glucuronic acid β (1-4) N-acetyl glucosamine L-Iduronic acid β (1-4) D-glucosamine Heparin sulfate : Contains glucuronic acid The most common disaccharide unit is and its glucosamine contains less sulfated 2-O-sulfated iduronic acid & 6-O-Sulfated, N- than heparin sulfated glucosamine (IdoA(2S)-GlcNS(6S) (also, second unit is called as glucosamine HS maintains interactions between bisulfate) cells and between cells and extracellular matrix. Heparin is present within basophils & mast Component of ECM of multicellular cells as secretary granules and is more sulfated animals & tissue specific HS variant HS stimulates adhesion of cells to ECM Blood anti-coagulant & used to treat heart by binding themselves to matrix attack etc. macromolecules such as Fibronectin and Laminin Summary  Proteoglycans When some They are found in mucous fluids, tissues, blood and in cell membrane. The carbohydrate content of glycoproteins is quite variable, it is 1% in collagen, 4% in IgG, 50% in mucins and 85% in the ABO blood group antigens.  Oligosaccharide linkages in glycoproteins: Proteins a) O-linked oligosaccharides have a glycosidic bond to the hydroxyl group amino acid side chain groups of Ser or Thr residues (light red), illustrated here with GalNAc as the sugar at the reducing end of the oligosaccharide. One simple chain and one complex chain are shown. b) N-linked oligosaccharides have an N- N-Acetylglucosamine (GlcNAc) glycosyl bond to the amide nitrogen Already amino of an Asn residue (green), illustrated derivative glucose residue here with GlcNAc as the terminal sugar. c) Three common types of N-glycosyl bonds join the anomeric carbon of a sugar to a nitrogen atom in glycoproteins oligosaccharide chains that are N- linked in glycoproteins are shown. d) A complete description of oligosaccharides structure requires to be specified on the position and stereochemistry (α or β) of each (Asn): glycosidic linkage. END  Red blood cells also depend on glycoproteins for their function. The type of glycoprotein on human red blood cells is referred to as the blood type. Red blood cells with type A blood have A antigens or A glycoproteins. As a result, the body learns that the blood is a component of oneself and is instructed not to fight it.  Due to their ability to facilitate sperm cell attachment to the egg’s surface, glycoproteins are essential for reproduction.  Glycoproteins called mucins are present in the mucus. The molecules protect delicate epithelial surfaces in the digestive, reproductive, urinary, and respiratory tracts.  Glycoproteins support the immunological response. The specific antigen to which an antibody (or glycoproteins) can bind depends on the carbohydrate it contains. Surface glycoproteins on B and T cells also bind antigens.  Glycoproteins also maintain the health of our skin. The epithelial cells that form skin have glycoproteins on their surface—these aid in bonding the skin cells in our bodies, creating a strong barrier to protect them. END  Other main difference between Proteoglycans: Unbranched, repeating They are found in mucous fluids, tissues, blood and in cell disaccharide units membrane. The carbohydrate content of glycoproteins is quite (amino sugars & Uronic variable, it is 1% in collagen, 4% in IgG, 50% in mucins and 85% acid) & (Also, sulfated in the ABO blood group antigens. or non-sulfate)d covalently attached to proteins Glycoproteins: Branched or unbranched and simple monosaccharides / amino-sugars (Glucose, Galactose, Mannose, Xylose, Fucose, N- acetylglucosamine, N- acetylneuraminic acid  Monosaccharide examples GLYCOPROTEINS Amino acid Examples of Oligosaccharide linkages in glycoproteins: LINKAGE aa Oligosaccharides Chain a a) O-linked oligosaccharides have a a Protein amino acid side chain groups glycosidic bond to the hydroxyl group of Ser or Thr residues (light red portion), Examples of Amino acid side chain groups: illustrated here with GalNAc as the sugar α at the reducing end of the oligosaccharide (terminal sugar). One simple chain and one complex chain are shown. b) N-linked oligosaccharides have an N- glycosyl bond to the amide nitrogen of an Asn residue (light green portion), β illustrated here with GlcNAc as the terminal sugar. (Asn) c) Three common types of oligosaccharide chains that are N-linked in glycoproteins N-Acetylglucosamine (GlcNAc) are shown. Already amino derivative glucose (GlcNAc)residue d) A complete description of N-glycosyl bonds join the anomeric carbon of a oligosaccharides structure requires to be sugar to a nitrogen atom in glycoproteins specified on the position and stereochemistry (α or β) of each Monosaccharide types (Any): glycosidic linkage Branched or unbranched and simple monosaccharides / amino- GlcNAc (N-acetyl glucosamine (amide derivative of the monosaccharide glucose) sugars (Glucose, Galactose, Man (Mannose – Aldohexose) Mannose, Xylose, Fucose, N- Neu5Ac (N-acetyl – a- neuraminic acid) acetylglucosamine, N- GalNAc (N-acetyl-galactosamine) acetylneuraminic acid  Carbohydrates & its derivatives N-linked glycosidic bond O-linked glycosidic bond  Proteoglycans VS Glycoproteins Main Differences between Proteoglycan & Glycoproteins Proteoglycan Glycoproteins A compound consisting of a protein Any class of proteins which have carbohydrate bonded to glycosaminoglycan groups attached to the polypeptide chain groups, present especially in connective tissue Attached to a protein to form a Attached to a protein to form a glycoprotein proteoglycan Chains attached are long, linear and Chains attached are short, negatively - charged Mainly occur in connective tissues Mainly occur on the cell membranes Provide structural support to ECM Serve as integral membrane proteins, which aid in cell recognition and signalling Classified based on the nature of the Two main types are N-linked glycoproteins and GAG O-linked glycoproteins Ex: Chondroitin sulphate, dermatan Ex: collagen, transferrin, mucin, Ig’s etc sulphate, keratan sulphate, heparin sulphate etc. Where all Glycoproteins present Different varieties of glycoproteins with various structures and activities can be produced due to the diversity of interactions. White blood cell identification depends on glycoproteins. The immune system uses a variety of glycoproteins, including,  Molecules that directly interact with antigens, such as antibodies (immunoglobulins).  Major histocompatibility complex or MHC molecules, which interact with T cells as a component of the adaptive immune response, are molecules expressed on the surface of cells.  Blood compatibility antigen H of the ABO blood type is another example of glycoprotein.  Gonadotropins (luteinizing hormone).  Components of the zona pellucida, which protects the oocyte and is essential for sperm-egg interaction.  Connective tissue also contains structural glycoproteins, facilitating the interaction between the connective tissue’s fibres and ground substance. Soluble glycoproteins often exhibit a high viscosity in blood plasma and egg white  List of Functions Nearly all cellular processes involve glycoproteins. They play various roles in our body, including those related to our immune systems, physical protection, cell-to- cell communication, and reproductive systems.  Glycoproteins are present on the lipid bilayer of cell membranes. They can operate in the aqueous environment due to their hydrophilic character, which plays a role in chemical bonding and cell-cell recognition.  Cell surface glycoproteins are crucial for cross-linking proteins (such as collagen) and cells to strengthen and stabilise a tissue.  Plants can resist gravity because of glycoproteins found in their cells.  White blood cells guard the blood arteries as they search for prospective invaders. They use lectin-type glycoproteins to adhere to the blood vessel lining.  Glycoproteins are present in the grey matter of the brain, where they collaborate with synaptosomes and axons.  The glycoproteins thrombin, prothrombin, and fibrinogen are necessary for blood coagulation.  Red blood cells also depend on glycoproteins for their function. The type of glycoprotein on human red blood cells is referred to as the blood type. Red blood cells with type A blood have A antigens or A glycoproteins. As a result, the body learns that the blood is a component of oneself and is instructed not to fight it.  Due to their ability to facilitate sperm cell attachment to the egg’s surface, glycoproteins are essential for reproduction.  Glycoproteins called mucins are present in the mucus. The molecules protect delicate epithelial surfaces in the digestive, reproductive, urinary, and respiratory tracts.  Glycoproteins support the immunological response. The specific antigen to which an antibody (or glycoproteins) can bind depends on the carbohydrate it contains. Surface glycoproteins on B and T cells also bind antigens.  Glycoproteins also maintain the health of our skin. The epithelial cells that form skin have glycoproteins on their surface—these aid in bonding the skin cells in our bodies, creating a strong barrier to protect them. END Following are the extra notes  PGs (In the ratio of 1:20 approx.) (Abundant) Scan ppt Scan ppt  Starch Linear D-glucose units (also called as Amylose) When it contains When it Branches with D-Glucose linear unit, Called as Starch (branched portion calls as Amylo-pectin) Scan ppt Other form of Carbohydrate polymers N-glycosyl bonds join the anomeric carbon of a sugar to a nitrogen atom in glycoproteins Scan Ppt Scan ppt Scan ppt  Lipopolysaccharides We will study the Lipids in the next class Please view the next ppt. for general structure of Lipopolysaccharide Scan ppt General Structure of Lipids  END Below are the normal ppts  N-glycosyl bonds join the anomeric carbon of different sugar to a nitrogen atom of amino acids of proteins in glycoproteins C6 converted to acidic Carboxylic group C1 converted to acidic Carboxylic group Esterified group  Glyco-Proteins Monosaccharide derivatives Combination of with different Polysaccharide+ Mano or Lipids+Amino acidsof Disaccharide units Glyco-Proteins linked with O- linked and –N linked Glycans (explained in the last few class) Hetero- Polysaccharide chain Look of Lipopolysaccharide Structures  Oxidation of one molecule of NADH @ Mitochondria leads to the Energy ATP Production by Glucose synthesis of three molecules of ATP, and Oxidation of FADH2, which enters the electron transport chain at complex II, yields only two ATP molecules Glycolysis / Glycolytic Pathway Krebs cycle or citric acid cycle Pyruvate is modified by removal of a carboxyl group followed by oxidation, and then attached to Coenzyme A. Total ATP/Glucose 2 oxidized=36 1 1 & 2 are basic interconvertible intermediates which build back monosaccharide's RED Arrows indicate ENERGY (ATP) producing points in living CELLS Carbohydrates are central to nutrition and are found in a wide variety of natural and processed foods. Starch is a polysaccharide and is abundant in cereals (wheat, maize, rice), potatoes, and processed food based on cereal flour, such as bread, pizza or pasta. Sugars appear in human diet mainly as table sugar (sucrose, extracted from sugarcane or sugar beets), lactose (abundant in milk), glucose and fructose, both of which occur naturally in honey, many fruits, and some vegetables. Table sugar, milk, or honey are often added to drinks and many prepared foods such as jam, biscuits and cakes. Cellulose, a polysaccharide found in the cell walls of all plants, is one of the main components of insoluble dietary fiber. Although it is not digestible by humans, cellulose and insoluble dietary fiber generally help maintain a healthy digestive system by facilitating bowel movements. Other polysaccharides contained in dietary fiber include resistant starch and inulin, which feed some bacteria in the microbiota of the large intestine, and are metabolized by these bacteria to yield short-chain fatty acids Carbohydrates, in their aminated forms, exist in humans -Extracellular matrix (ECM) -Cell antigens etc. Surrounding cells Industrial applications Behave like anchors -Fabrics etc. Signaling molecules etc Particular examples of PGs embedded in Plasma Membrane Some more examples Some more examples Glycoconjugates The structures of some typical intact on cell membrane proteoglycans, glycoproteins, and glycosphingolipids Linear Glucose units in Amylose  Examples, where can they exist ? Poly saccharide cellulose fibers That’s how cellulose exist Carbohydrate Metabolism : Basics Biotechnological Applications Biotechnological Applications  END Below are the normal ppts Carbohydrate Metabolism: (Key Points) Carbohydrate Metabolism (CM) is a biochemical process for metabolic NADH Formation Breakdown of carbohydrates Inter conversion See next ppt Directly In mitochondria produced Indirectly produces ATP Plants synthesis carbohydrates from Carbon dioxide See next ppt and water through photosynthesis. Ex: Cellulose (polymer of Glucose units) Animal / Human after absorption of degraded products of complex carbohydrates (Carbohydrate polymers), (TCA) each units. Ex. Glycogen etc. highly Glucose Likely to break down further in a process For example: Fructose known as respiration (or) glycolysis, and (Through Auto feed back) inducing Mannose synthesis energy molecules takes place. (Where glycogen gets degraded to glucose) Galactose They may also again under go polymerization to form Glycogen (storage (Instead of breaking down) carbohydrates) Respiration in plants involves the use of sugars produced during photosynthesis plus oxygen to produce energy for plant growth. Scan ppt Each Glucose converts into 3”C” atom intermediates (Dihydroxy acetone Phosphate & Pyruvate). Each Pyruvate gets converted into 3CO2 in TCA/Krebs Cycle. Therefore, = CO2 two cycles of TCA, removes 6”C’ of Glucose into 6CO2.  Glycogen (Glucose polysachhride) breaks down into glucose and glucose-1-phosphate reaction takes place in the hepatocytes, kidney cells and myocytes regulation of two key enzymes: phosphorylase kinase and glycogen phosphorylase. See next PPt (F-6-P an intermediate in Glycolytic PW) & Intermediates like= Dihydroxy-acetone Phosphate & Glyceraldehyde & Pyruvate (see previous ppt)  A glucogenic amino acid is an amino acid that can be converted into glucose through gluconeogenesis (i.e., synthesis of glucose) Glycolysis ketogenic amino acid is an amino acid that can be degraded directly into acetyl-CoA. This Acetyl-CoA enters into TCA/Krebs cycle for break down & also converts into Fatty acid and Fatty acid converts to Glucose Every conversion is an enzyme catalysed step by respective enzyme Red (Glucogenic means, converted only to Glucose Green (Ketogenic means, converted to acetyl-CoA Purple (both glucogenic & ketogenic) This means, they converted directly to Glucose & acetyl Co-A TCA / Citric acid / Krebs Cycle These amino acids break down and produce “Intermediates of TAC/Krebs cycle” Glucose also produced by Amino Acids in addition to Gluconeogenesis This PW generates NADPH and pentoses (5- carbon sugars) as well as ribose 5-phosphate, a Due to precursor for the synthesis of nucleotides (DNA). and a prefer method. Biotechnological Applications Biotechnological Applications