Crystallization of Enantiomerically Pure Proteins from Quasi-Racemic Mixtures: Structure Determination by X-Ray Diffraction of Isotope-Labeled Ester Insulin and Human Insulin.

Publication Type:

Journal Article

Authors:

Mandal, Kalyaneswar; Dhayalan, Balamurugan; Avital-Shmilovici, Michal; Tokmakoff, Andrei; Kent, Stephen B H

Source:

Chembiochem, Volume 17, Issue 5, p.421-5 (2016)

Keywords:

Crystallization, Crystallography, X-Ray, Esters, Insulin, Isotope Labeling, Models, Molecular, Protein Conformation, Proteins, Stereoisomerism

Abstract:

<p>As a part of a program aimed towards the study of the dynamics of human insulin-protein dimer formation using two-dimensional infrared spectroscopy, we used total chemical synthesis to prepare stable isotope labeled [(1-(13) C=(18) O)Phe(B24) )] human insulin, via [(1-(13) C=(18) O)Phe(B24) )] ester insulin as a key intermediate product that facilitates folding of the synthetic protein molecule (see preceding article). Here, we describe the crystal structure of the synthetic isotope-labeled ester insulin intermediate and the product synthetic human insulin. Additionally, we present our observations on hexamer formation with these two proteins in the absence of phenol derivatives and/or Zn metal ions. We also describe and discuss the fractional crystallization of quasi-racemic protein mixtures containing each of these two synthetic proteins.</p>

PDB: 
5ENA
Detector: 
PILATUS
Beamline: 
24-ID-C