Issue 46, 2021

Structure–mechanical property relationship of a pentapeptide crystal

Abstract

The structure–mechanical property relationship of a synthetic pentapeptide crystal containing coded and non-coded amino acids was presented. Pentapeptide 1 has two α-aminoisobutyric acid (Aib) residues at 2 and 4 positions and formed an orthorhombic crystal, with the space group P212121, which is sensitive to external stress and brittle in nature. From FE-SEM the crystal appears as a thick bundle of several fibers. The structural analysis of a crystal of pentapeptide 1 obtained in methanol–water confirmed the existence of an unusual secondary structure, a miniature (P)310/α-helix. The pentapeptide 1 molecules self-assemble by intermolecular N–H⋯O hydrogen bonds and form a supramolecular helical bundle structure which further assembles to form a supramolecular sheet-like structure along the crystallographic a and c directions. The intermolecular interaction energies (kJ mol−1) for pentapeptide 1 were calculated using the B3LYP/6-31G(d,p) dispersion corrected DFT model. Although the interaction energy is small, there is no sign of slippage due to the interdigitation of the Leu i-propyl, Boc t-butyl, and Phe side chains. As a result, the crystal is brittle in nature. Moreover, the quantitative nanoindentation technique reveals the moderate E and H values for the major face of this crystal, which is consistent with the presence of adequate van der Waals interactions and several hydrogen bonding interactions in the structure.

Graphical abstract: Structure–mechanical property relationship of a pentapeptide crystal

Supplementary files

Article information

Article type
Paper
Submitted
04 6 2021
Accepted
11 10 2021
First published
12 10 2021

CrystEngComm, 2021,23, 8093-8098

Structure–mechanical property relationship of a pentapeptide crystal

S. K. Nandi, S. Mondal, S. Mondal, M. Gumtya and D. Haldar, CrystEngComm, 2021, 23, 8093 DOI: 10.1039/D1CE00738F

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements