Related Experiment Video
Updated: Sep 15, 2025
Staphylococcus aureus Growth using Human Hemoglobin as an Iron Source
Published on: February 7, 2013
Purification, Crystallization, and Preliminary X-ray Diffraction Studies on Hemoglobin from the Angora Goat (Capra
Farheen Pervez1, Shobana Nagaraj2, Mpho Setshedi1
1Protein Structure-Function Research Laboratory, School of Molecular and Cell Biology, University of the Witwatersrand, Johannesburg 2050, South Africa.
Introduction:
Angora goats are a distinct breed that differs significantly from common goats and shares a similar appearance to sheep. In Angora goats, only the level of glutathione (GSH) is elevated during under-stimulated conditions, as well as after the period of hypoxic stress; however, no changes are found in 2,3-diphosphoglycerate (2,3-DPG) levels, which are commonly present in the red blood cells (RBCs) of most mammals. We chose the Angora goat for our investigation because no previous studies have been conducted on the structural and functional aspects of hemoglobin (Hb). In addition, no sequence or structural information is currently available in any database.
Methods:
Angora goat Hb was isolated and purified by anion-exchange chromatography, followed by crystallization using various methods. X-ray data collection for Angora goat Hb was performed under a liquid nitrogen cryo-stream using a Bruker D8 Venture Bio Photon III 28-pixel array area detector system.
Results:
Good diffracting crystals were obtained using the hanging-drop vapor-diffusion method with polyethylene glycol (PEG) 3350 as the precipitant in water, without the addition of any salt or buffer. The Angora goat Hb diffracted to a resolution of 1.85 Å, and the structure solution was obtained by the molecular replacement method, using the structure of domestic goat Hb as the starting model.
Discussion:
The solved structure of Angora goat crystallized in the monoclinic space group P21, consisting of one whole biological molecule in the asymmetric unit, with unit cell dimensions of a = 52.08 Å, b = 76.70 Å, c = 74.08 Å, and β = 91.77 °. The solvent content and Matthews coefficient (Vm) for the Angora goat Hb are 49.05% and 2.41 Å3/Da, respectively, and are within the normal range for protein crystals.
Conclusion:
Purification, crystallization, and preliminary X-ray diffraction studies of Angora goat Hb were performed successfully. Structural refinement and biophysical characterization of Angora goat Hb are in progress in the absence and presence of GSH and 2,3-DPG.
More Related Videos
08:58Characterization of Glycoproteins with the Immunoglobulin Fold by X-Ray Crystallography and Biophysical Techniques
Published on: July 5, 2018
10:50Purification and Analytics of a Monoclonal Antibody from Chinese Hamster Ovary Cells Using an Automated Microbioreactor System
Published on: May 1, 2019
