Peptide sequence or amino acid sequence is the order in which amino acid residues, connected by peptide bonds, lie in the chain. The sequence is generally reported from the N-terminal end containing free amino group to the C-terminal end containing free carboxyl group. Peptide sequence is often called protein sequence if it represent the primary structure of a protein.
Proteins are polymers whose amino acid sequence is specified by a gene encoded in the genetic code.
Protein is also a necessary component in the diet of humans and other animals that cannot synthesise all amino acids and must obtain essential amino acids from their diet.
Consequently, numerous alternative theories of the protein primary structure were proposed, e.g., the colloidal hypothesis that proteins were assemblies of small molecules, the cyclol hypothesis of Dorothy Wrinch, the diketopiperazine hypothesis of Emil Abderhalden and the pyrrol/piperidine hyopthesis of Troensgard (1942).
Proteins are found in every cell and are essential to every biological process, protein structure is very complex: determining a protein's structure involves first protein sequencing - determining the amino acid sequences of its constituent peptides; and also determining what conformation it adopts and whether it is complexed with any non-peptide molecules.
Discovering the structures and functions of proteins in living organisms is an important tool for understanding cellular processes, and allows drugs that target specific metabolic pathways to be invented more easily.
The amino acid sequence of a protein can also be determined indirectly from the mRNA or, in organisms such as prokaryotes that do not have introns the DNA that codes for the protein.
Share your thoughts, questions and commentary here
Want to know more? Search encyclopedia, statistics and forums:
Press Releases |
The Wikipedia article included on this page is licensed under the
Images may be subject to relevant owners' copyright.
All other elements are (c) copyright NationMaster.com 2003-5. All Rights Reserved.
Usage implies agreement with terms, 1022, m