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Antithrombin III

Antithrombin III works to inhibit the activity of thrombin, and it is produced in liver and vascular endothelial cells. Thrombin is a serine protease (a kind of protein-degrading enzyme) that plays an important role in the production of blood clots. Heparin is thought to bind to antithrombin III and enhance its anti-thrombin activity by approximately 1000 fold.


Energy sources that organisms can use are sugars, fats and proteins, but the chemical source of energy to promote the chemical reaction of cell metabolism is adenosine triphosphate (ATP). ATP enables cells to synthesize or degrade various chemical substances. The cells can then use these metabolic products.



This term literally signifies the fusion of bioscience and informatics. Computer technology that is helpful for various research and development activities, including investigations of life information such as amino-acid sequences in protein or DNA base sequences, as well as the development of medicines and agricultural chemicals.

Blood glucose level

Concentration of glucose in blood. The normal values in humans are 70 to 100 mg/100 ml between meals or when starving and 150 to 160 mg/100 ml after eating. When the blood glucose level becomes below 60 mg/100 ml, brain function is disrupted, and when it exceeds 170 mg/100 ml, glucose is released into urine.


Classification of glucides

Glucides hydrolyzed to a unit which cannot be further broken down to other sugars are called "monosaccharides". When two to six monosaccharides are linked they are called "oligosaccharides" and seven or more are called "polysaccharides". Monosaccharides are represented by glucose, fructose, and galactose, and typical oligosaccharides are sugar (compound of glucose and fructose) and lactose (compound of glucose and galactose), which are explained in the text. Starch, chitin, and cellulose are classified as polysaccharides.

Complex glucides

When multiple sugars are linked they form a "sugar chain" (it may be a straight chain or branched). "Complex glucides" is a generic term for substances in which polymers, other than sugars, are bound to the sugar chains and can be classified into three types: glycolipids (linkage between sugar and lipid), glycoproteins (linkage between sugar and protein), and proteoglycans.
Proteoglycans are common to glycoproteins at the point where sugar and protein are bound, but different because a huge sugar chain (glycosaminoglycan) having a structure where a simple repeat of two sugars is linked to protein or sulfate moiety always exists.
Hyaluronic acid, sometimes mentioned in Japanese TV commercials for cosmetics is treated as a proteoglycan, which is a glycosaminoglycan without a linkage to protein or a sulfate group.


Double helix model of DNA

The DNA structure presented by Watson and Crick in Nature, the prestigious natural science journal, in 1953. Since then, molecular genetics has been progressing rapidly together with the advancement of technology to manipulate and analyze DNA, enabling human genome projects.


Extracellular matrix

A generic term for substances secreted by cells, and normally referring to animal tissues other than cells. Bone, cartilage, tendon, and dermis of skin are representative extracellular matrix (ECM), and the main ingredients are fibrous structural proteins such as collagen, glycoproteins, and proteoglycans.
Conventionally, the chief purpose of the extracellular matrix was believed to support cells and the body. It has been discovered, however, that when cells are incubated under an environment different from living organisms, the characteristics of cells are changed. This discovery has attracted attention to cell-to-ECM adhesion.


Fibroblast Growth Factor (FGF)

FGF works as a growth regulator, neoangiogenesis, or wound healing of fibroblasts, adrenal cells or chondrocytes. Over 10 members of the FGF family have currently been identified, including FGF-2 (basic FGF).


Genetic Engineering

Genetic engineering refers to the science of rendering different modifications to a particular gene extracted from an organism, expressing it in, for example, E. coli, yeast, or cultured cells, to examine its function or to look for where it can be applied. Genetic engineering has made dramatic advances as a result of the discovery of a group of enzymes that cleaves or joins genes, the discovery of various vectors that can be used for the introduction or proliferation of a particular gene, and progress in and automation of methods for determining base sequences.


The entire system of genes that reproductive cells possess. In 1920, far before the time the double helix model of DNA was announced, the term "genome" was used as an expression to indicate a set of chromosomes.


A substance in which about 20,000 glucoses are linked, and whose molecular weight is several million. In the sense of the linkage of multiple glucoses, glycogen is commonly referred to as starch. Starch, however, is characterized by a molecular weight of several thousand to several hundred thousand (equivalent to 20 to 2,000 glucoses) at the most, with less branching than glycogen. It is known that starch is a storage polysaccharide in plants and glycogen is that in animals.


A generic term for substances in which sugar is attached to protein. Glycoprotein widely exists in the living world from animals and plants to microorganisms. Protein is synthesized based on the "blueprint" in DNA (called "translation" ). It is believed that sugar chains are added to about half the protein in animal cells after translation. The addition of sugar chains plays an important role to enhance and diversify the functions of protein.


An enzyme which has the function to add sugar and is essential for producing complex glucides. About 170 glycosyltransferases have been cloned so far.


Helicobacter pylori

Discovered in 1983. Once Helicobacter pylori was eliminated from hard-to-treat or recurrent ulcer patients, they showed a high cure rate. Because of this, H. pylori is now widely recognized as one of the causes of gastric ulcers and duodenal ulcers. Although papers strongly suggest a potential link to stomach cancer, there is a report that 80% of Japanese people over 40 years old are infected with H. pylori, and the relevance is not yet clear.

Heparin, Heparan sulfate

A structure in which sulfuric acid is bound to sugar chains contained in proteoglycans such as chondroitin sulfate or sugar chains repeating two types of sugars of glucuronic acid and N-acetylglucosamine or iduronic acid.
Heparan sulfate is a glycosaminoglycan which exists in the basement membrane or surface of the cell, and known as heparan sulfate proteoglycan (perlecan, syndecan, glypican, or agrin). Heparin is different from heparan sulfate from the point of its high degree of sulfation or high ratio of components having an anticoagulation effect. Heparin, however, is known to be synthesized only by mast cells, so the major role of coordinating cell multiplication is considered to be played by heparan sulfate, which is widely distributed in animal cells and tissues.

Hepatitis B virus

Pathogen causing hepatitis B which spreads via body fluids or blood. The host of this virus is the liver cell and the virus itself does not destroy the liver cells. However, the immune system, which detects the invasion of foreign matter, attacks the liver cells infected with the virus, resulting in inflammation.

Herpes virus

The term "herpes" comes from the fact that a blister-like skin inflammation is called "herpes" and over 100 types of this virus have been found in the natural world. It is known at present that there are eight types of herpes viruses, which are infectious to humans, including the virus causing chickenpox.

Hyaluronic acid

As explained in Part 1, it is a typical example of glycosaminoglycans and has a straight-chain structure in which two sugars of N-acetyl-D-glucosamine and D-glucuronic acid are in line with one another. In the living body, hyaluronic acid normally exists as a polymer of several million in molecular weight. Structural difference by animal species has not been discovered.



A hormone having the effect to reduce the blood glucose level and which is secreted from the pancreas (islet of Langerhans). Insulin was discovered by Banting and Best in 1921 and the complete chemical structure was revealed by Sanger in 1956.


A generic term for animals having no vertebral column, which means all animals except for vertebrates.


Monoclonal antibody

An antibody which is produced making use of a characteristic by which only one type of antibody is produced from one antibody-forming cell and is composed of uniform molecules developed by biotechnology.


Monoclonal antibody

Neuramidinase is an enzyme essential for proliferation of influenza virus types A and B. Agents that show anti-viral effect by inhibiting their activity are called neuramidinase inhibitors. Neuramidinase exists on the membrane surface of the influenza virus, and plays an important role when the virus is "released" from the infected cell. Neuramidinase inhibitor suppresses the activity of neuramidinase so that the virus cannot be "released" from the infected cell, and is therefore considered especially useful in the initial stage of infection when the influenza virus has not sufficiently proliferated.
Representative neuramidinase inhibitors include Tamiflu and Relenza.



A compound in which multiple amino acids are bound to each other, it is generally referred to as a "peptide" and if the number of such component amino acids exceeds 10, it is called a "polypeptide" .


Proteoglycan is a collective term for a substance in which a giant sugar chain (glycosaminoglycan or mucopolysaccharide) consisting of simple repeated structure of disaccharide is bound to a protein and always includes a sulfate component. It is the same as glycoprotein in that sugar and protein are bound together, but distinguished from glycoprotein in that a giant sugar chain is bound to the protein.
Representative proteoglycans include hyaluronic acid, heparin, heparan sulfate, chondroitin, chondroitin sulfate, dermatan sulfate, and keratan sulfate.

Proteoglycan Analogue

A group of substances which have structures similar to a given substance is generally called an analogue (or analogous compound) of that substance. For example, proteoglycan analogues refer to a group of substances which have structures similar to a proteoglycan. Since chitin and chitosan contained in the shell of crab and shrimp are a kind of mucopolysaccharide that constitutes a proteoglycan, they are classified as proteoglycan analogues.


Regeneration medicine

Treatment which regenerates tissues or organs lost by disease or accident through a technique such as cell culture or the administration of a physiologically active agent.



A generic term for animals including fish, amphibians, reptiles, birds, and mammals. These animals have a bone structure as the axis to support their bodies. The term "vertebrate" derives from the fact that this axis is called the "vertebral column".