Glyco‐Scan: Varying Glycosylation in the Sequence of the Peptide Hormone PYY3‐36 and Its Effect on Receptor Selectivity

Abstract

The increasing prevalence of obesity worldwide calls for safe and highly efficacious satiety drugs. PYY3-36 has been implicated in food intake regulation, and novel peptide analogues with high Y2 receptor-subtype selectivity and potency have potential as drugs for the treatment of obesity. It has been hypothesized that PYY3-36 associates with the plasma membrane prior to receptor activation such that the amphipathic alpha-helix of PYY3-36 possibly guides the C-terminal pentapeptide into the correct conformation for receptor activation. Ala-scans are used routinely to study the effect of individual amino acids in a given peptide sequence. Here we report the glyco-scan of the peptide hormone PYY3-36, in which hydroxyl side-chain functionalities were glycosylated; in addition new glycosylation sites were introduced. An array of novel PYY3-36 analogues with a glycan positioned in the water-membrane interface or in the N terminal were screened for Y-receptor affinity and selectivity as well as metabolic stability. Interestingly, in contrast to the Y1 and Y4 receptors, the Y2 receptor readily accommodated glycosylations. Especially glycosylations in the alpha-helical region of PYY3-36 were favorable both in terms of Y-receptor selectivity and endopeptidase resistance. We thus report several PYY3-36 analogues with enhanced Y-receptor selectivity. Our results can be used in the design of novel PYY analogues for the treatment of obesity. The glyco-scan concept, as systematically demonstrated here, has the potential for a wider applicability.

CNS active O-linked glycopeptides

“…Therefore, when a helical system is required in a peptide, studies must be made on a case-by-case basis to determine if glycosylation will affect the peptide secondary structure. Jensen and coworkers took into account these considerations while designing and running a targeted “glycoscan” (substituting native peptides for either a serine glucoside or serine galactoside) of analogs of PYY3-36, a peptide implicated as a potential therapeutic for obesity (Pedersen et al, 2010 ). The researchers noted that selective installation of carbohydrates increased the half-life of their peptides against two proteases, while affecting helicity (both positively and negatively) and receptor affinity in a site-dependent manner.…”

Ca2+-Responsive Glyco-insulin

“…Glycosylation of therapeutic peptides and proteins is known to improve the pharmacodynamic and pharmacokinetic profile, often without leading to immunogenicity. − Furthermore, the hydrophilic nature of glycans can increase the solubility and prevent aggregation . The improvement of the serum half-life of insulin has also been achieved through sialic acid conjugation .…”

Solution Structure and Constrained Molecular Dynamics Study of Vitamin B12 Conjugates of the Anorectic Peptide PYY(3–36)

“…In earlier work, we focused on conjugating to B 12 through the ribose hydroxy group, as it is well established in the field that this is an optimal site for such conjugation, as it does not hinder recognition of B 12 by its carrier proteins . Likewise, we focused on an N‐terminal region of PYY(3–36) for conjugation (specifically the K 4 residue), because again it has been well documented that modifications at (or indeed complete loss of) this area do not significantly affect Y2‐R agonism . These assumptions bore out, as the EC 50 values at the Y2‐R obtained for the conjugate produced (and noted as conjugate 3 herein) were similar to that of unconjugated PYY(3–36) used for comparison.…”