What are Peptides?
Peptides consist of a small amino acid jointed by peptide bonds. This bond is the same peptide that holds together proteins, but in this case, the length of the peptide is shorter than that of the protein. If they are 50 amino acids or more are involved in a chain the resulting compound is called a protein, while chain will less than 50 are peptides. The peptide bond that holds the amino acids together is a covalent bond (formed when two atoms share electrons). The bond is formed by two molecules through the reaction of the carboxyl (-COOH) interacts with amino group (NH3). The shortest peptide is a dipeptide, which is formed by two amino acids, which are held together by a peptide bond. The list doesn’t end; there are also tri-peptides, tetra-peptides, and so on. The peptides have an end with an amino and a carboxyl. On the other hand, a polypeptide consists of single series of amino held together by a peptide bond. Proteins are made up of one or more polypeptides joined biologically, they at time have non-peptides group attached to them known as cofactors or prosthetic groups. All creatures on earth contain peptides in their bodies, which in a way makes it essential for life. There are endless possibilities on the roles played by proteins and peptides in the body, that why molecular biologist have spent years looking into these endless possibilities and to learn in detail about them.
As the name suggests milk peptides are produced from the milk protein by digestive enzymes during an enzymatic break down or during fermentation of milk by the lactobacilli. Several of the milk proteins have been known to cause antihypertensive effect on animals.
The peptides are manufactured by the translation of mRNA. This function is found in higher organisms in processes as gesturing molecules and hormones. While other organism produce peptides as antibodies. Since they are produced during translation the leftover amino acid controlled to the use by ribosomes.
These are peptides produced by enzymes, which are specific to a particular peptide, as opposed to the ribosome. The widely known nonribosomal is known as glutathione, which used as antioxidant defense in aerobic organisms. The non-ribosomal can also be found in unicellular organisms’ fungi and all plants; the modular enzyme complexes in a process known as the non-ribosomal synthesis produce them.
Peptones are found in animal milk and meat; they are digested through the proteolytic digestion. Apart from peptides the peptones are contain fats, salts, metals, vitamins and other compounds. Peptones are also used for growing fungi and bacteria.
Peptides fragments such as GHRP-2, GHRP-6 and Melanotan 2 (MT-2) play a very important role in the lab, there are used to detect the source of protein. The fragments are as a result of enzymatic degradation for controlled experiments in the labs.
The Roles of Peptides in Body
A peptide has many roles to play in the body, but this depends on the type of amino acid used in the process. Some peptides are used to regulate the hormone level, in antibiotic functions. The body can also break down and reuse the peptides whenever it wants. For example, when a person consumes meat the enzymes in the intestines use the protein in the meat to come up with assortments of peptides types. These peptides are either digested or removed by the body, but this will depend on the requirements of the body. The following lists of peptides are ribosomal peptides that take part in some of the hormonal activities. They are found in the blood where they perform their respective functions.
Tachykinin Peptides, are strong vasodilator and they can contract indirectly or directly. They are found smooth muscles.
Vasoactive Peptides, it is responsible for vaginal lubrication and they are also located in the heart, where it has a role to play on the cardiovascular system.
Pancreatic Polypeptide, related peptides, they are located in the pancreas where they regulate the colon and pancreatic functions.
Opioid Peptides, have a critical role in emotional response, motivation, pain and stress. They also have control over food intake.
Calcitonin Peptides, it the most wide spread peptide and is found in the central nervous system and the peripheral system. It has a role to play intransmission of pain.