A proopiomelanocortin‐derived peptide sequence enhances plasma stability of peptide drugs

Abstract

Bioactive peptide drugs hold promise for therapeutic application due to their high potency and selectivity but display short plasma half‐life. Examination of selected naturally occurring peptide hormones derived from proteolytic cleavage of the proopiomelanocortin (POMC) precursor lead to the identification of significant plasma‐stabilizing properties of a 12‐amino acid serine‐rich orphan sequence NSSSSGSSGAGQ in human γ3‐melanocyte‐stimulating hormone (MSH) that is homologous to previously discovered NSnGGH (n = 4–24) sequences in owls. Notably, transfer of this sequence to des‐acetyl‐α‐MSH and the therapeutically relevant peptide hormones neurotensin and glucagon‐like peptide‐1 likewise enhance their plasma stability without affecting receptor signaling. The stabilizing effect of the sequence module is independent of plasma components, suggesting a direct effect in cis. This natural sequence module may provide a possible strategy to enhance plasma stability, complementing existing methods of chemical modification.

C‐terminal tails mimicking bioactive intermediates cause different plasma degradation patterns and kinetics in neuropeptides γ‐MSH, α‐MSH, and neurotensin

“…Tyto alba and human to ‐MSH peptides retained longer biological activity in plasma when including C‐terminal natural extensions 14,15 . Here, we opted for the (bio)‐chemical analysis of synthetic human analogues γ2‐MSH* (YVMGHFRWDRFG‐NH 2 ) and γ3‐MSH (YVMGHFRWDRFGRRNSSSSGSSGAGQ) (Table 1, Figure 1B).…”

“…Tyto alba and human to -MSH peptides retained longer biological activity in plasma when including C-terminal natural extensions. 14,15 Here, we opted for the (bio)-chemical analysis of synthetic human analogues γ2-MSH* (YVMGHFRWDRFG-NH 2 ) and γ3-MSH (YVMGHFRWDRFGRRNSSSSGSSGAGQ) (Table 1, Figure 1B). Since biological activity is a downstream readout to the actual concentration of the MSHs, we first investigated whether this reading directly correlates with a different decay of the two peptides in plasma.…”

“…34 We found that γ2-MSH* and γ3-MSH were cleaved at Arg6 with similar kinetics ( Figure 4B). Indeed, the percentage of cleavage at 5 min is approximately 62% for γ2-MSH* and approximately 60% for γ3-MSH ( Figure S3), resulting in comparable [1][2][3][4][5][6]/ [7][8][9][10][11][12] and [1][2][3][4][5][6]/ [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] fragment ratios, respectively. Longer incubations induced further fragmentations with appearance of multiple shorter sequences ( Figure S3, Table S1).…”

“…Recent studies conducted on peptides derived from bird species and human POMC demonstrated γ3-MSH versus γ2-MSH residual activity after incubation in blood plasma. 14,15 The POMC system consists of α-, β-, and γ-melanocyte stimulating hormones (MSHs) that activate five melanocortin receptors (MC1-5R). 16 MSHs are short peptides (11)(12)(13)(14)(15)(16)(17)(18) residues), generated by proteolysis of the common POMC precursor.…”

“…In this scenario, an interesting peptide system is represented by the pro‐opiomelanocortin (POMC) protein complex (Figure 1A,B). Recent studies conducted on peptides derived from bird species and human POMC demonstrated γ3‐MSH versus γ2‐MSH residual activity after incubation in blood plasma 14,15 . The POMC system consists of α‐, β‐, and γ‐melanocyte stimulating hormones (MSHs) that activate five melanocortin receptors (MC1‐5R) 16 .…”