Polypeptides are chains of amino acids. Proteins are made up of one or
more polypeptide molecules.
polypeptide is a long, continuous, and unbranched peptide. Proteins
consist of one or more polypeptides arranged in a biologically
functional way and are often bound to cofactors, or other proteins.
amino acid polymer is known as a polypeptide. A polypeptide can be
composed of 20 different possible monomers that can, in theory, be
linked together in any imaginable order.
contrast to peptides, polypeptides function as hormones that trigger
specific physiological processes. In humans, hormone secretions of
polypeptides occur in the endocrine system through a series of glands
distributed throughout the body.
Polypeptide growth factors are a diverse group of hormone-like agents
that regulate growth and differentiation through cell surface receptors.
potential solution to the conundrum of polypeptide hormone specificity
has recently emerged in a series of articles detailing the intranuclear
translocation and action of peptide ligands and their receptors, or
Acceptance of an intranuclear function for polypeptide ligands and their
receptors, however, is not universal. This may be due to a lack of a
larger perspective on the intranuclear action of all ligand/receptor
complexes. Many of the concerns regarding the function of intranuclear
polypeptide ligand/receptors can be addressed by examining the parallels
that exist with other acknowledged signaling pathways.
Despite the amount of technology developed for recombinant protein
production, optimization of the expression strategy is often needed for
a large number of proteins or peptides. Factors that need to be
considered are production and recovery in sufficient yield of the active
Peptide thioesters are versatile synthetic intermediates that are useful
in polypeptide synthesis. For example, native chemical ligation using
peptide thioesters as building blocks is a very useful and convenient
method for polypeptide synthesis.
general chemical requirements for the synthesis of peptide involve the
blocking of carboxyl group of one amino acid and the amino group of the
second amino acid.
methods for the synthesis of peptides are the ringopening polymerization
(ROP) of amino acid N-carboxyanhydrides (NCAs) and solid-phase
display is a powerful technology for engineering polypeptides that bind
virtually any target, and also for in- vestigating the binding speciącities
of natural protein ligand interaction.
use of bacterially expressed peptide segments in combination with
chemically synthesized ones as building blocks offers great potential as
a route to the synthesis of a wide variety of polypeptides.
Proopiomelanocortin (POMC) is the polypeptide precursor of ACTH. First
discovered in anterior pituitary corticotroph cells, it has more
recently been revealed to have many other physiological aspects.
utilisation of peptide synthesis technology in solving health problems
of worldwide importance was mainly dictated by the desire to obtain
stable products devoid of the various contaminants often seen in
recombinant material (glycosylation variants, proteases, DNA, endotoxins)
in record time and in reasonable quantities to perform preclinical