We created the structure collection feature in Molecule World because I knew it would be useful in teaching my courses. A request from the Weisman Art Museum at the University of Minnesota taught us structure collections could be useful in other ways, too.
The Weisman Art Museum collaborated with neuroscientists at the University of Minnesota and Ricardo Martinez Murillo, a neuroscientist in Spain, to produce the traveling Beautiful Brain exhibit featuring the drawings of Santiago Ramón y Cajal. Cajal is considered the father of modern neuroscience and is famous for his detailed drawings of neurons and structures in the brain. We saw the exhibit in Minneapolis. I was struck by the resemblance between this drawing of a neuron and the roots of a tree.
In the exhibit, Cajal's wonderful drawings are presented together with modern visualizations of brain cells and structures. We were happy to contribute by making a structure collection with receptor proteins from brain cells.
If you want to see The Beautiful Brain, the remaining exhibits are:
May 2 - Dec. 31, 2018 MIT Museum, Massachusetts Institute of Technology, Cambridge, MA, USA
Jan 27 - Apr 7, 2019 Ackland Art Musem, Universityof North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
Whether or not you attend the exhibit, you can still explore the Beautiful Brain structure collection, from an iPhone or iPad using Molecule World. If you have Molecule World on an iPhone, touch the links for individual structures to download them and open them in the app. If you have Molecule World on an iPad, you can download the entire collection at once by touching the link that ends in "mwc".
Ideas for exploring the Beautiful Brain Collection
Go to the Beautiful Brain Collection. You'll find a sodium channel, potassium channels from rat and bacteria, and an amino acid receptor.
1. Where is the membrane-spanning region?
Change the drawing mode to Spacefill and the coloring style to Charge. Use the Show/Hide menu to show all atoms. Use the color key to identify where the protein has a neutral charge.
2. What charge do you see for amino acids near the opening of the channel? What is a likely charge for the ion that goes through the channel?
In the image above, in the top left, the channel opening is in the middle of the protein. Using the Molecule World color key shows how the four amino acids near the opening are charged.
3. What unusual amino acid is found in this protein?
Open the sequence viewer, then find and touch an X. Hide everything else and zoom in. Use the color key to identify the element. Two amino acids are known to contain this kind of element. Can you figure out which amino acid this is?
4. What type of secondary structure is found in the membrane spanning region?
Touch the Secondary View button and use the color key to identify the type(s) of secondary structure found in this protein. Color by charge to see where this protein spans the membrane.
Potassium channels from bacteria and rats
1. Where does the potassium pass through this channel?
Color these proteins by element. Use the color key to identify the potassium.
2. In what ways are the rat and bacterial potassium channels similar (or different)?
Here are some strategies you might try:
Use the Secondary View to identify types of secondary structure.
Color by charge to identify the membrane-spanning regions.
Color by molecule to identify the number of subunits.
Amino acid receptor / ion channel
Where is the membrane-spanning region of this protein?
Change the drawing style to space fill and color by charge. Use the color key to identify the part of the protein with a neutral charge.