Orn Almarsson’s favorite structure is:

Itraconazole succinic acid cocrystal

image

Source: JACS

Why?

Crystal structure analysis has been central to the design of pharmaceutical cocrystals in the past decade in the quest for new materials for drug discovery and development. Intermolecular interactions in this pharmaceutical cocrystal are counterintuitive: the strongest base in the drug molecule is not involved in hydrogen bonding or proton transfer – Packing drives the shape of the complex of 2:1 drug:diacid. This knowledge helped to design other materials with new properties, such as improved dissolution for oral delivery. —Orn Almarsson

Alan Ehrlich’s favorite structure is:

no one structure in particular

Why?

As a patent attorney, I often get rejections of patent applications by Examiners based on similarity of compositions in the prior art. Often, the
similarity is replacement of one component in a crystal with one of another component of different ionic radius or charge. I am usually successful in pointing out the strain on a crystal from such replacements such that the seeming similarity should not adversely affect patentability.—Alan Ehrlich

Andrea Alsobrook Bridges’s favorite structure is:

NDTB-1

image

Why?

Dr. Thomas Albrecht Schmitt's NDTB-1 (Notre Thorium Borate-1) is one of my favorite crystal structures because it demonstrates a color change occurring between the single crystals. As the anions were exchanged, the colors of the transition metals appeared. These colored crystals remind me of my graduate work performed in his research group. I incorporated first-row transition metals into uranium phosphonate systems.  This resulted in colored crystals that were due to electronic coupling from the 5f-3d electrons.—Andrea Alsobrook Bridges

Jason Hein’s favorite structure is:

racemic and enantiopure ribo-aminooxazole

IMG_8324

Source:
http://www.nature.com/nchem/journal/v3/n9/pdf/nchem.1108.pdf%3FWT.ec_id%3DNCHEM-201109

Why?

This molecule has been identified as possibly one of the earliest progenitors to RNA on a pre-biotic earth. This simple product, formed by the condensation of HCN and formaldehyde is so important because it easily crystalizes from solutions containing complex mixtures of product, allowing it to accumulate in the environment and "outlast" normal breakdown. This purification and sequestration by crystallization also has another very important feature; it allows the molecule to separate as a single enantiomer. This is a critical feature, as without enatiopure starting material RNA self replication would not be possible. The key question was weather ribo-amino-oxazole preferentially crystalized in its enantiopure or racemate form. Moreover, we needed to know how it would spontaneously nucleate from a very complex reaction mixture to mimic how this may be relevant to a pre-biotic environment. Our study showed that while the pure ribo-amino-oxazole tended to form a racemate crystal (and thereby would allow both enantiomers to accumulate), it prefers the enatiopure crystal from when nucleated from complex reaction mixtures. This study offers a glimpse at RNA could have been formed spontaneously and may offer proof as to why all RNA and DNA exists as a single chirality.—Jason Hein

Kreisler Lau’s favorite structure is:

DNA double helix

Why?

Dawn of modern biology in cell metabolism and genetics, Mother Nature's masterpiece, the DNA structure elucidation research was effectively aided by some phenomenal X-Ray crystallography work by Rosalind Franklin. It was a pity that her work was often overlooked as a result of her untimely passing too young to receive the Nobel Prize. The winners list of the prize should have been Crick, Watson Franklin, & Pauling.  The record stands as Crick, Watson and Wilkins.—Kreisler Lau

Ginger Sigmon’s favorite structure is:

U60

image

Source:

Why?

This is a structure grown during my PhD work. The crystals look like yellow diamonds and have the structure of U60. U60 is an uranium peroxide nanocluster containing sixty identical polyhedra. The structure is isostructural to the C60 buckminster fullerene but is approximately 2.5 nm in size.  I have it with me at all times in an image on my watch.—Ginger Sigmon

Michael James’s favorite structure is:

SGPB

SGPB

Source: ACA Newsletter 2009

Why?

SGPB is a serine protease from a bacterium that has a fold similar to that of mammalian trypsin. It was the first protein structure to be determined in Canada in 1974. It has played an important role in determining the sequence to reactivity algorithm of Michael Laskowski Jr.—Michael James

Charles Evans’s favorite structure is:

Time-resolved crystallography of myoglobin ligand dissociation

image

Source: J Struct Biol, 2004, 147, 235

Why?

This was the highlight of my undergraduate course in protein structure and dynamics. The animation is a time-resolved combination of x-ray crystal structures of myoglobin's haem binding site. From the electron density maps you can see not only the amino acid residues of the active site, but also the movement of the dissociating ligand and the residues of the active site. The visualisation of protein fluctuation on such a scale is truly beautiful!—Charles Evans

Charles Evans’s favorite structure is:

Ligand binding structures of myoglobin

Ligand binding structures of myoglobin

Source: Nature 404, 205-208 (9 March 2000)

Why?

A highlight of my undergraduate course in protein structure and dynamics, this series of crystal structures have been animated to show the conformational changes around the haem site of myoglobin. You can see the movement of the dissociated CO around the site, and the movement of individual amino acid residues as the local environment changes. It's truly beautiful to watch a protein's dynamics in such close detail!—Charles Evans

Geoffrey Price’s favorite structure is:

Zeolite Beta

GeoffreyPriceWithZeoliteModels

Why?

My favorite crystal is zeolite beta, an intergrowth of two polymorphs, which I am holding in the picture. You can think of beta somewhat like taking these two models, shaving them into layers, and shuffling them like a deck of cards. I originally saw the structure of beta in 1985 in the Mobil Princeton labs where I had taken a consulting job working in Roland vonBallmoos’ group. The structure fascinated me because one of the polymorphs contains a spiral pore. Could it be grown in enantiomeric forms? Could it be used to separate enantiomers of organic compounds? But in my exit interview, I was told specifically that the structure of beta was one the top secrets of the company. Nothing could be said about it. Scroll forward 4 years to 1989 at Exxon Clinton labs. I was again a consultant and was in the office of John Newsam. Sitting on his desk was model of a zeolite. I picked it up to examine it, and because of the spiral pore, I recognized it as zeolite beta. 30 years later, I am still fascinated enough to build a digital model of the structure and have the two polymorphs printed.—Geoffrey Price

Hao-Bo Guo’s favorite structure is:

MerR

MerR2

Source: JMB

Why?

We actually do not have a crystallographic structure of the mercuric ion Hg(II)-dependent transcription regulator, MerR. We only have the low-resolution envelope shape from small-angle X-ray scattering. However, combining SAXS and
molecular dynamics simulations we were able to refine this structure and visualize the opening-and-closing principal dynamics of the Hg(II)-bound MerR.—Hao-Bo Guo

Helen’s favorite structure is:

G-Protein Coupled Receptor Kinase 2

Why?

G-protein coupled receptor kinase 2 is an up and coming target for heart failure. It's crystal structure is useful for those of use working on designing inhibitors as therapeutics for heart failure. Mutagenesis studies have
shown that targeting specific amino acids is difficult. The crystal structure is very important as it is the entire conformation of the protein that we need to understand and the crystal structure helps to reveal this.—Helen