Metal ion scavenging activity of elastin-like peptide analogues containing a cadmium ion binding sequence

Shogo Sumiyoshi,Daiki Tatsubo,Keitaro Suyama,Iori Maeda,Suguru Taniguchi,Keisuke Tomohara,Naoki Tanaka,Takeru Nose

doi:10.1038/s41598-022-05695-w

Shogo Sumiyoshi, Daiki Tatsubo + Show 6 more

Open Access

https://doi.org/10.1038/s41598-022-05695-w

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Abstract

The development of simple and safe methods for recovering environmental pollutants, such as heavy metals, is needed for sustainable environmental management. Short elastin-like peptide (ELP) analogues conjugated with metal chelating agents are considered to be useful as metal sequestering agents as they are readily produced, environment friendly, and the metal binding domain can be selected based on any target metal of interest. Due to the temperature dependent self-assembly of ELP, the peptide-based sequestering agents can be transformed from the solution state into the particles that chelate metal ions, which can then be collected as precipitates. In this study, we developed a peptide-based sequestering agent, AADAAC-(FPGVG)4, by introducing the metal-binding sequence AADAAC on the N-terminus of a short ELP, (FPGVG)4. In turbidity measurements, AADAAC-(FPGVG)4 revealed strong self-assembling ability in the presence of metal ions such as Cd2+ and Zn2+. The results from colorimetric analysis indicated that AADAAC-(FPGVG)4 could capture Cd2+ and Zn2+. Furthermore, AADAAC-(FPGVG)4 that bound to metal ions could be readily recycled by treatment with acidic solution without compromising its metal binding affinity. The present study indicates that the fusion of the metal-binding sequence and ELP is a useful and powerful strategy to develop cost-effective heavy metal scavenging agents with low environmental impacts.

Highlights

The development of simple and safe methods for recovering environmental pollutants, such as heavy metals, is needed for sustainable environmental management
Turbidity measurements of AADAAC-F4 demonstrated that this peptide exhibited coacervation ability similar to that observed for the original (FPGVG)n analogues
The self-assembly ability of AADAAC-F4 was significantly enhanced in the C d2+-containing solution

Summary

Introduction

The development of simple and safe methods for recovering environmental pollutants, such as heavy metals, is needed for sustainable environmental management. We found that phenylalanine-containing synthetic ELPs consisting of (FPGVG)n sequences exhibited strong coacervation ability at a significantly low number of repetitions (n = 5)[44], whereas (VPGVG)n required a relatively high repetition number (n > 40) to exhibit coacervation ability[45,46,47] By mimicking such repetitive sequences, various ELP analogues composed of Xaa-Pro-Gly-Val-Gly (XPGVG where X = I, F, and W) pentapeptide repeats have been developed[44, 47,48,49,50,51]. During these experimental studies, we discovered that nitrilotriacetic acid (NTA)-conjugated short ELP analogues could bind to several metal ions, such as copper or n ickel[52].

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