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glyclys1.txt
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1993-12-14
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Jon Maber
=========
5th May 1993
============
(Update postscript 12th May 1993)
There are several files - three from Toolbook and one
molecular graphics animation.
What you need
=============
You need run-time Video for Windows. If you were at St Andrews
and attended the Toolbook stuff run by Frank you will have
an installation disc for it already. (Look in the pocket at the
back of the manual.)
If I get many requests I'll put it on the server.
As to hardware a 256 colour screen would be nice for the molecular
graphics and plenty of RAM is advisable. If you only have a slow
386 you can fiddle with the Vid4Win config. to get the best results.
More later.....
Getting the files
=================
These files are not compressed or archived in any way because they
are already well compressed images. They are binary so switch into
binary mode (also use hash command with the big files so you know the
machine hasn't crashed).
Running the Movies
==================
Run the Media Player programme. You should have an icon for this
somewhere in your Windows Desktop (picture of unwinding reel of film
stock.) Use File-Open to open a file.
transprt.avi
------------
This is a short clip showing one model for the operation of a membrane
bound transport protein. The file is short, well-compressed and so should
run OK even on a slightly slower machine. Because it is short you
might like to get Media Player to Loop the sequence. You can do this
with the Edit Options... dialog box. Tp get a good look at the
crucial part where the red blob crosses the membrane stop the movie,
drag the slider to get the blob just above the protein and then use the
advance frame button to step though the next few frames. This way
you can see the conformational change at your leisure!
g-spot.avi
----------
This is an example of how this method wins out over the straight
toolbook animation. There are several objects moving at the same
time. When played back in toolbook the screen refresh is very poor
(jerky). It works out much smoother this way. (By the way the
name of the file is a red herring - it's no where near as exciting
as you think.)
On a slow PC you may get a jerky display. This is because frames
are skipped when it lags behind. For animation you would prefer
a smooth transition but slowed down a bit. You can set it to do
this. After you have loaded the file in go to the 'Confiure...'
command of the Device menu. In the dialog box switch off 'Skip
video frames if behind' option.
glyclys1.avi
------------
This is a very short clip from a longer movie I produced. The movie
follows through the whole of glycolsis. It has more than 700 frames
and lasts several minutes - the picture size is much bigger than
you usually see for 'live' video clips. This is possible because
of the good compressiion. The file is about 4Mbytes (the complete
movie).
This clip is much shorter. I found the frame refresh was poor for
this one on my office machine but I have a very old 16MHz 386 with
a high res 256 colour display.
ketglu.avi
----------
This shows a shaded space filling model of alpha ketoglutarate rotating
first about the y axis then the x axis. Swicth off the 'Skip
video frames if behind' option on a slower PC for a smooth effect.
Switch on Auto Repeat on the Options... dialog to get an endless
loop. I am seriously thinking about putting together a small
library of these movies for use in tutorial material - there are some
advantages over linking in with a molecular graphics package.
1) You don't have to teach the students how to use it.
2) Some students have poor 3d visualisation and can't rotate a
molecule to its desired orientation even if you show them the
knobs and buttons. (Also they waste time getting the perfect
picture.)
3) You don't need to shell out cash for more multi license software.
4) If you choose a good starting position and appropriate transforms
the user can use the media player controls to see any feature/group
they want to.
Drawbacks....
1) You can't smoothly switch between stick and space fillling models.
You would have to make separate movies.
2) For bigger molecules you might need the interaction provided by
proper mol. graph. programmes.
3) The picture size is limited. With the shading compression is
intermediate to the Toolbook animations and 'live' video.
Things to try...
1) Space filling models of proteins. Doing the rotations as for small
molecules doesn't work very well. For a given angle of rotation the
atoms being smaller jump across the screen with each frame. This means
you have to turn very slowly to get a smooth image. There are two
ways rounf this. a) position to get a good view of feature and rock
the molecule from side to side to get the 3d effect. (much as
you might move your head from side to side when threading a needle.)
b) go to some simpler representation e.g. ribbon with side chains
added at active site.
Making your own movies
======================
When I've polished it up I'll put the original Toolbook files on
the server with some authoring notes. Authoring with Vid4Win as
your target is even easier than normal because you don't worry about
the performance of Toolbook and if there are glitches you can cut
them out later. You can also paste together sequences so you
can break down the problem into managable chunks.
Let me know what you think of these.
Jon Maber
----------------------------------------------------------------------