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see peptidepeptide,
organic compound composed of amino acids linked together chemically by peptide bonds. The peptide bond always involves a single covalent link between the α-carboxyl (oxygen-bearing carbon) of one amino acid and the amino nitrogen of a second amino acid.
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an organic compound containing six to 80–90 amino acid residues; the upper limit corresponds to a molecular weight of about 10,000. Such polypeptides, unlike proteins, can pass through semipermeable membranes.

The simple polypeptides are crystalline substances that are readily soluble in water and have chemical properties similar to those of amino acids. The complex polypeptides are amorphous and react with water to yield colloidal solutions. Polypeptides are formed in the organism during enzymatic proteolysis (autolysis of tissue, digestion, and so on) and during biosynthesis from amino acids. Many natural polypeptides exhibit the biological activity of hormones, antibiotics, and toxins. Synthetic polypeptides serve as models in studying the structure and biological activity of proteins.


A chain of amino acids linked together by peptide bonds but with a lower molecular weight than a protein; obtained by synthesis, or by partial hydrolysis of protein.
References in periodicals archive ?
Polypeptide analysis of purified hydatid cyst fluids of different species (Sheep, goat, cattle, buffalo, camel and human) was performed under reduced conditions to evaluate number of polypeptides and their molecular weights in each species.
Butler, "Human islet amyloid polypeptide oligomers disrupt cell coupling, induce apoptosis, and impair insulin secretion in isolated human islets," Diabetes, vol.
Rob Hutchison, CEO said the company's team worked with Transcend in pre-clinical models to prove its utility to delivery therapeutic agents across the BBB as well as conducted over four years of experiments to find active polypeptide fragments from within the 738 amino acid sequence of Transcend that were involved in binding specific receptors that are involved in transport through the BBB.
Polypeptide profile of chromium resistant cyanobacteria strains Synechocystis sp.
The primary component of islet amyloid and actual fibril-forming molecule is human islet amyloid polypeptide (hIAPP or amylin), a 37-residue peptide which is synthesized in pancreatic islet [beta]-cells and cosecreted with insulin.
The properties of different protein products of genes are determined by the sequence of amino acids of the polypeptide chain and by the way in which the chain is folded.
2010).However to broaden the genetic base for nutritional quality improvement of maize seeds it is imperative to assess the diversity of zein polypeptides in maize germplasm.Germplasm are a vital source of gene and play key role in crop improvement.
multocida isolates was carried out using SDS-PAGE along with known protein marker for determination of polypeptides of bacteria revealed in separating gel (figure 2).
Stimuli responsive elastin-like polypeptides and applications in medicine and biotechnology.
Both polypeptides are weak polyelectrolytes and LbL films from such polymers have been reported not to be rigid [20].
Interestingly, several of the polypeptide bands that remained in the [P.sub.TX-100] fraction, including the polypeptides of approximately 68-70 kDa, 52-55 kDa, and 27-31 kDa, were immunorecognized by sera from bovines experimentally and naturally infected with T.
The determination of molecular weights was based on the distance migrated by the polypeptides in the gels in comparison to the distance migrated by polypeptide markers of known molecular weights (Biored) [22].