Effect of antifreeze activity and lipid interaction of tryptophan scanning of 11-residue lysine homopeptide
Year: 2024
Type: conference-paper
Abstract: Antifreeze peptides and proteins play crucial roles in the survival of organisms that thrive in cold environments, such as polar fish [1].These compounds serve diverse functions, including cryopreservation, which is essential for organisms facing freezing conditions.Peptides exhibit varied primary and secondary structures, offering a range of functionalities in cold adaptation.In our study, we focused on an 11-residue lysine homopeptide, K11, where each position was substituted with Trp using a scanning technique.Peptides were synthesized using the Fmoc/tBu strategy [2], followed by purification and characterization via RP-HPLC and mass spectrometry.Antifreeze activity of peptide was evaluated using differential scanning calorimetry (DSC) and quantifying ice recrystallization inhibition, known as thermal hysteresis (THA).Results showed a slightly increased antifreeze activity with fewer remaining nucleation points across all peptides in the scanning sequence.Substituting internal residues whit Trp, enhanced ice recrystallization inhibition, highlighting the significance of peptide structure.However, Trp substitution disrupted the secondary structure of K11, as obtained by circular dichroism, notably affecting the type II polyproline helix of K11 and resulting in decreased antifreeze activity compared to the K11 homopeptide.This highlights the intricate relationship between peptide structure and functionality in antifreeze mechanisms. ABSTRACT Effect of antifreeze activity and lipid interaction of tryptophan scanning of 11-residue lysine homopeptideAntifreeze proteins (AFPs) are expressed in fish that inhabit the polar zones, allowing them to survive in environments at temperatures below zero.This physical property is considered of enormous importance in the cryopreservation of cells, tissues and organisms.There are different types of secondary structure for AFPs.The exact mechanism by which these molecules exert the antifreeze effect has not been fully clarified at present.In order to appreciate changes in the structure of proteins, a study of lysine peptide (K11) is carried out as well a series in which each position of the peptide K11 chain was replaced by tryptophane (Scan-W) (Fig. 1).They present secondary polyproline II structure (PPII) that has diehedral angles φ = -75 and ψ = +145 and φ = -75 and ψ +160 for PPI (Fig. 2A).
Source: European Peptide Symposium (EPS)
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: bronze
OpenAlex ID: W4404738010