Introduction to Peptides

What Is a Peptide?

A peptide is a natural chemical compound that contains two or more amino acids connected by by bonds peptide bonds. A peptide bond is a covalent bond that forms between two amino acids when a carboxyl group o C end of one amino acid reacts with the amino group o N end of another amino acid in a reaction of condensation (during the reaction a water molecule is released). The resulting bond is a CO-NH bond and shape peptide or amide molecule. Likewise, peptide bonds are amide bonds.

The word "peptide" comes from the Greek πέσσειν, meaning "to digest." Peptides are a essential part of the nature and biochemistry, and thousands of peptides occur naturally in the human body and in animals. Furthermore, New peptides are discovered and synthesized regularly in the laboratory. In fact, this discovery and innovation in the study of peptides is very promising for the future in the fields of health and development pharmaceutical.

How Are Peptides Formed?

Peptides are formed both naturally within the body and synthetically in the body. laboratory. The bodysuit It manufactures some peptides organically, such as ribosomal and non-ribosomal peptides. In the laboratory, the Modern peptide synthesis processes can create a virtually unlimited number of peptides using techniques such as liquid phase synthesis or solid phase synthesis. Although the synthesis in liquid phase has Some advantages, the synthesis of peptides in solid phase is the standard process used today in day.

The first synthetic peptide was discovered in 1901 by Emil Fischer in collaboration with Ernest Fourneau. The Oxytocin, the first polypeptide, was synthesized in 1953 by Vincent du Vigneaud.

Peptide Terminology

Peptides are generally classified according to the amount of amino acids they contain. The peptide more short, Composed of only two amino acids, it is called a "dipeptide". Likewise, a peptide with 3 amino acids are known as "tripeptide". Oligopeptides refer to shorter peptide compounds by a number relatively small amino acids, generally less than ten. Polypeptides, on the other hand, are usually compounds by more de al minus ten amino acids. The much larger peptides (those compounds by more than 40-50 amino acids) They are generally called proteins.

Although the number of amino acids contained is a main determinant to differentiate between peptides and proteins, exceptions are sometimes made. For example, certain longer peptides have been considered proteins (as amyloid beta), and certain smaller proteins are called peptides in some cases (such as insulin).

Classification of Peptides

Peptides are generally divided into several classes. These classes vary depending on how produce peptides. By For example, ribosomal peptides are produced from the translation of mRNA. The peptides ribosomal often Works as hormones and signaling molecules in the body/organisms. These may include tachykinin peptides, vasoactive intestinal peptides, opioid peptides, pancreatic peptides and calcitonin. The Antibiotics such as microcins are ribosomal peptides produced by certain body/organisms. The peptides Ribosomal cells often undergo the process of proteolysis (the breakdown of proteins into peptides smaller or amino acids) to reach its mature form.

In contrast, nonribosomal peptides are produced by specific enzymes of peptides, not by the ribosome (as in ribosomal peptides). Non-ribosomal peptides are frequently cyclic in linear place, although linear non-ribosomal peptides can often occur. non-ribosomal peptides can develop cyclic structures are extremely complex and appear frequently in plants, fungi and body/organisms unicellular. Glutathione, a key part of the antioxidant defenses in body/organisms aerobics, is the peptide not ribosomal more common.

Milk peptides are formed from milk proteins. They can be produced for decomposition enzymatic production by digestive enzymes or by proteinases formed by lactobacilli during the fermentation of the milk. Furthermore, peptones are peptides derived from animal milk or meat that have been digested by digestion proteolytic. Peptones are often used in the laboratory as nutrients for mushroom cultivation and bacteria.

Peptide fragments, furthermore, are more commonly found as degradation products enzymatic performed in the laboratory on a controlled sample. However, peptide fragments also can occur naturally as a result of degradation by natural effects.

Terms Importantes sobre Peptides

There are some basic terms related to the peptides that are key for an understanding general of the themselves, their synthesis and their use in research and experimentation:

• Amino Acids
• Cyclic Peptides
• Peptide Sequence
• Peptide Bond
• Peptide Mapping
• Peptide Mimetics
• Peptide Fingerprint
• Peptides Library