Peptide interactions with crystalline and nanoparticle materials

Abstract

Three of the peptides tested demonstrate intriguing effects on the crystal size and shape distributions. Additionally, phage display was explored as a potential technique for identifying peptide motifs for calcium oxalate monohydrate affinity, but abandoned due to procedural concerns. Cysteine containing peptides were tested for the ability to achieve the longitudinal assembly and functionalization of gold nanorods. UV-vis was used to measure the linking ability of the peptides, and this data was compared to the linking of gold nanorods by alkane dithiols, a known gold nanorod linker. Two cysteine containing peptides demonstrated UV-vis spectra consistent with the longitudinal assembly of gold nanorods. These results demonstrate the ability of peptides to achieve binding affinity to inorganic materials which could have applications in medicine, energy, and advanced materials, as well as effective methods for screening peptides for their beneficial properties in the areas of crystal shape engineering and nanoparticle assembly.

Peptides are a class of molecules which offer a high degree of functional flexibility and simplicity which can be leveraged to develop molecules with high affinity and specificity toward a target. In this work, peptides are investigated for their efficacy in binding to crystalline and nanoparticle inorganic materials. In particular, peptides were screened for the growth inhibition of calcium oxalate monohydrate crystals and the ability to longitudinally link gold nanorods. A robust assay was developed for the high throughput screening of peptides, utilizing Fmoc peptide synthesis, automated image collection, and a machine learning algorithm to analyze images. This assay was used to evaluate the effects of peptide growth modifiers derived from osteocalcin in comparison to calcium oxalate crystal growth without modifiers and also with a known modifier.