Main subjects:
1.1. Structure of amino acids. Peptide bond
1.2. Structural organization of proteins
1.3. Physicochemical properties of proteins
1.4. Structure and functioning of hemoglobin
1.5. Structure and functions of immunoglobulins
1.6. Main techniques of separation and purification of proteins
Proteins are macromolecular nitrogen-containing organic compounds whose structure has been studied since the mid 18th century. Dutch scientist Gerrit Jan Mulder at the beginning of 19th century discovered that the proteins are polymers built up of б-amino acids and proposed the term «proteins» (from the Greek protos, for the first) stressing the major role of these compounds in nature. The term «proteins» was used in Russia for the compounds secreted from the organism and resembled hen?s egg white.
In human body proteins make up almost ¼ of body mass (about 15 kg). Proteins provide the basis of the cell?s structure and are vital for all living cells. Phenotypic features and a variety of functions of each organism are conditioned by diversity in protein composition.
More than 50 000 proteins of human body are known to perform the following functions:
• catalytic; the acceleration of chemical reactions is realized by enzymes making up >50% of all proteins;
• protective; immunoglobulins (antibodies), complement system, lysozyme, lactoferrin etc., protection of the body against bacterial toxins, foreign proteins and other macromolecules;
• transport; the transport of different substances by blood occurs with the help of proteins, for example serum albumin (Na+ ions, fatty acids etc.), transferrin (iron ions), hemoglobin (oxygen);
• regulatory; protein hormones control the cellular metabolism (insulin, glucagon, vasopressin etc.);