With peptides proving to be highly effective at delivering results for a wide range of conditions, they are continuing to gain popularity among consumers as well as professionals. As a result, uk peptides have become increasingly commonplace in the marketplace and are being sold by sellers on e-commerce platforms such as Amazon. The main image for the product CJC 1295 on Amazon UK, for example, states that it is a ‘research peptide not intended for human consumption’ and the text under it claims that it will help increase muscle mass, reduce body fat, improve workout recovery times and enhance immune system function.
The majority of bioactive peptides described to date have systemic effects and therefore must be either absorbed from the intestine or reach target cells or receptors via cell signalling in order to cause their effect. The gastrointestinal tract is capable of absorbing di- and tripeptides relatively easily but a much more difficult task lies ahead for higher molecular weight bioactive peptides.
For the most part, these peptides have to either be pre-hydrolysed or resistant to digestive enzymes in order to be absorbed from the intestinal tract. This can be achieved through bacterial fermentation processes, as in the case of cheese ripening or the use of exogenous pre-hydrolysed peptides such as the lactoferrins and immunoglobulins from milk.
However, there is evidence that some bioactive peptides may have direct gastrointestinal effects and can be released from proteins such as casomorphins (released from a-casein), b-lactorphins and serorphin from serum albumin. These peptides act as opioid agonists with morphine-like activity and can affect the various mu opioid receptors in different ways. The m-receptor can influence appetite, pain sensation and emotion whilst the d-receptor influences behaviour and the k-receptor regulates satiety signals and intestinal motility.
Clearly, there is still a long way to go in the field of bioactive peptides to understand how best they can be used for optimal health benefits. In the future this may mean that a whole range of diseases could be treated with functional foods rich in these bioactive peptides.
As such, the special issue begins with four Reviews on transformative peptide technologies that have recently been developed. The first by Professor Marc Vendrell at the University of Edinburgh provides an excellent overview of fluorescent cyclic peptides and discusses their synthesis, characterisation and applications.
This is followed by a Review from Professor Andrew Wilson at the University of Leeds that focuses on structural optimisation of reversible maleimide-based helix constraints and the application of this to the design of a series of model peptides. Finally, Dr Gary Laverty from Queen’s University Belfast discusses the production of a library of linear lipopeptides inspired by polymyxins. These peptides can be used to label fungal and bacterial cells with fluorescence, enabling direct observation of infection by confocal microscopy. These peptides also show great promise for the development of cost-effective and rapid diagnostic tools. uk peptides