Biotechnology Archive

Digestion of Proteins by Proteases

Proteases (also known as proteinases or peptidases ) hydrolyze the peptide bond between amino acid residues in a polypeptide chain. Proteases may be specific and limited to one or more sites within a protein, or they may be nonspecific, digesting …

Westren Blotting of Proteins

Often researchers will use Western blotting to identify proteins. Western blots rely on having an antibody to the protein. Antibodies are extremely specific and will bind only to one target protein. The first step is to separate the proteins by …

Gel Electrophoresis OF Proteins

Studying proteins requires the ability to isolate and identify the proteins in a particular sample. The first step is to separate them. Much as electrophoresis on agarose gels is used to separate DNA by size, so polyacrylamide gel electrophoresis (PAGE) …

Proteomics

Today we have the genome sequences for humans as well as many other animals, plants, fungi, and bacteria. All these data have given scientists a global view of the various genes in humans and others. However, genes are only the …

Immune Memory and Vaccination

Individuals who survive an infection normally become immune to that particular disease, although not to other diseases. This is because the immune system “remembers” foreign antigens, a process called immune memory . Next time the same antigen appears, it triggers …

Monoclonal Antibodies For Clinical Use

    There are many clinical uses for antibodies. They are used in diagnostic procedures (including the ELISA), for pregnancy testing, and to detect the presence of proteins characteristic of particular disease-causing agents. In the future, they may be used …

Antibody Structure

Each antibody consists of four protein subunits, two light chains and two heavy chains , arranged in a Y-shape. Disulfide bonds between cysteine amino acid residues hold the chains together. Each of the light and heavy chains consists of a …

The Great Diversity of Antibodies

Antibodies are proteins that recognize and bind to alien molecules. Because there are an almost infinite variety of possible alien molecules, a correspondingly vast number of different antibody molecules are needed. The amino acids making up protein molecules can certainly …

Antibodies, Antigens, and Epitopes

Antigen The term antigen refers to any foreign molecule that provokes a response by the immune system. In practice, most antigens are proteins made by invading bacteria or viruses. In particular, glycoproteins, which carry carbohydrate residues, and lipoproteins, which carry lipid …