Ahmed Syeda Tajin, Zhai Sixin, Huang Xin, Sulaja Sarvagya, Adewole Adekunle, Ioffe Alisa, Merg Andrea D, Yan Jing, Eguiluz Roberto C Andresen
Department of Chemical and Materials Engineering, University of California, Merced, Merced, CA 94344, USA.
Materials and Biomaterials Science and Engineering Graduate Group, University of California Merced, Merced, CA 94344, USA.
bioRxiv. 2025 Aug 29:2025.08.25.672170. doi: 10.1101/2025.08.25.672170.
In this letter, the pull-off forces of adsorbed films of four Bap1-inspired peptides in various solvents were investigated on negatively charged mica substrates using the surface forces apparatus (SFA), complemented with dynamic light scattering (DLS) for characterizing the aggregation behavior of peptides in solution. Bap1-inspired peptides consisted of the 57 amino acid wild-type sequence (WT); a scrambled version of the WT used to investigate the impact of the primary amino acid sequence in pull-off forces (Scr); a ten amino acid sequence rich in hydrophobic content (CP) of the WT sequence, and an eight amino acid sequence (Sh1) that corresponds to the pseudo-repeating sequence in the 57 AA. SFA results showed remarkable pull-off forces for CP, particularly in the presence of salts: measured pull-off forces were 26.0 ± 7.0 mN/m for no dwell-time and up to 42.0 ± 8.8 mN/m when surfaces were left in contact for 30 minutes. DLS observations indicate that salts favor large peptide aggregation for all constructs ( > 1 μm), as compared to milliQ ( ≈ 100-500 nm) water and DMSO ( ≈ 100 nm), resulting in heterogeneous peptide film thicknesses. This letter concludes with a comparison to the pull-off forces of mussel foot protein-inspired peptides reported in the literature.
在这封信中，使用表面力仪（SFA）在带负电荷的云母基底上研究了四种受Bap1启发的肽在各种溶剂中吸附膜的拉脱力，并辅以动态光散射（DLS）来表征肽在溶液中的聚集行为。受Bap1启发的肽包括57个氨基酸的野生型序列（WT）；WT的一个打乱版本，用于研究一级氨基酸序列对拉脱力的影响（Scr）；WT序列中富含疏水成分的十个氨基酸序列（CP），以及对应于57个氨基酸中伪重复序列的八个氨基酸序列（Sh1）。SFA结果显示CP具有显著的拉脱力，尤其是在有盐存在的情况下：无停留时间时测得的拉脱力为26.0±7.0 mN/m，表面接触30分钟时可达42.0±8.8 mN/m。DLS观察表明，与超纯水（≈100 - 500 nm）和二甲基亚砜（≈100 nm）相比，盐有利于所有构建体形成大的肽聚集体（>1μm），导致肽膜厚度不均匀。这封信最后将其与文献中报道的贻贝足蛋白启发的肽的拉脱力进行了比较。
