July 2011 - Chimera-users - RBVI Mailing Lists

Chimera function
by Flora Ieong 07 Jul '11

07 Jul '11

To whom it may concern, I am a chimera user and am currently doing a glycan research using Chimera 1.5.3. I wonder if chimera has a function to add glycans to a protein. Thank You. Sincerely, Pek Ieong

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movie script
by Jean-Francois Menetret 06 Jul '11

06 Jul '11

Hello, I am trying to make a movie to illustrate a conformational change between two PDBs; I would like to turn the objects while switching from one to the other. Could you give me some pointers ? Thank you J-F

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Re: [Chimera-users] Drug-Metal Complexation Modeling
by Mickey Branham 06 Jul '11

06 Jul '11

Thanks Elaine, I did check out the CCL website; a great resource. Mickey >>> Elaine Meng 07/05/11 6:25 PM >>> Hi Mickey, I don't have experience in this area, but you might try asking on the Computational Chemistry List (www.ccl.net) as to what programs might be suitable for predicting the structure of your complex. One way is to use their web form http://www.ccl.net/cgi-bin/ccl/send_ccl_message Best, Elaine ---------- Elaine C. Meng, Ph.D. UCSF Computer Graphics Lab (Chimera team) and Babbitt Lab Department of Pharmaceutical Chemistry University of California, San Francisco On Jul 2, 2011, at 1:46 AM, Mickey Branham wrote: > Thanks Elaine, > Yes, your comments were helpful. I did a bit of window shopping with Chimera (very impressive) but I think for this project it may not be the right set of tools. Briefly, what we're trying to do is to produce stable complexes of the dipeptide carnosine with a heavy metal (i.e. ruthenium III) by high energy ball milling. > > So far this approach has been effective in producing nanosized particles which do contain [carn-Ru] complexes (ca. XRD, DSC/TGA, and FTIR) but their structure and molecularity appear to be polydispersed. > > We are trying to predict the most stable complex stoichiometry so that we can optimize milling parameters (e.g. temp, inert gas, speed and time) known to influence complex formation rate. Once we are able to reproducibly form the [carn-Ru] complex our plan is to characterize its anti-viral or anti-tumor activty. > > Don't know if this seems interesting but any comments from you would be appreciated. > > Thanks again for your response. > > Cheers > Mickey Please find our Email Disclaimer here: http://www.ukzn.ac.za/disclaimer/

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Not Responding
by Chad Junkermeier 05 Jul '11

05 Jul '11

Hello, I have been having strange behavior lately with opening coordinate files. I am using xyz format files with up to 500 atoms. When I tell Chimera to open one of these files the computer sits for a moment and then starts reporting that Chimera is "Not Responding." I have tried this on three different Mac computers, one using OS X 10.6.7 (iMac Core i7, 8 GB Ram, ATI Radeon HD 4850) with all of the latest updates, one using OS X 10.6.7 (iMac Core 2 Duo, 4 GB Ram, NVIDIA GeForce 9400), and one 3 or 4 year old Macbook that has (4GB RAM, and I don't know anything else). On each of these machines I have tried using a variety of different versions of your code, and I continually find that I have the same problem. I also just installed Chimera on a Windows XP machine and it has similar issues. The xyz files are the product of relaxing a graphene sheet in Quantum Espresso, and then copying and pasting the final configuration out of the QE output file into a xyz file. Here are a few of the things that puzzle me. First, if I place the input configuration of atoms into a xyz file, Chimera will read in the structures without any problems. The output xyz files work in VMD and in iMol. I thought that it might be an issue with the xyz data structure and transformed it to PBD and it still wouldn't load. I also wondered if it was an issue of too many decimal points (higher precision than the input file), but after reducing the number of decimal points of each coordinate on all of the atoms, it still wouldn't work. I have looked through some of the output files and there doesn't appear to be any weirdness in any of the files. Further complicating this issue is that sometimes, after if I let it sit for a while, the program magically starts working. Again, I have no problem opening other files. Does anyone have any ideas on what to do to fix this problem? Chad

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Re: [Chimera-users] Drug-Metal Complexation Modeling
by Mickey Branham 05 Jul '11

05 Jul '11

Thanks Elaine, Yes, your comments were helpful. I did a bit of window shopping with Chimera (very impressive) but I think for this project it may not be the right set of tools. Briefly, what we're trying to do is to produce stable complexes of the dipeptide carnosine with a heavy metal (i.e. ruthenium III) by high energy ball milling. So far this approach has been effective in producing nanosized particles which do contain [carn-Ru] complexes (ca. XRD, DSC/TGA, and FTIR) but their structure and molecularity appear to be polydispersed. We are trying to predict the most stable complex stoichiometry so that we can optimize milling parameters (e.g. temp, inert gas, speed and time) known to influence complex formation rate. Once we are able to reproducibly form the [carn-Ru] complex our plan is to characterize its anti-viral or anti-tumor activty. Don't know if this seems interesting but any comments from you would be appreciated. Thanks again for your response. Cheers Mickey >>> Elaine Meng 06/23/11 6:23 PM >>> Hello Mickey, Chimera has a "Metal Geometry" tool for assessing the coordination geometry within metal complexes, for example, identifying a protein complexation site as octahedral vs. pentagonal bipyramidal. It is intended for use with existing coordinates, such as from crystallography or output by other computational methods. Chimera does not include QM calculations, and would not replace the programs you mention if you are primarily interested in generating the coordinates in the first place. You can build structures with Chimera, but optimization is rather limited to only a few metals, and those that are handled are treated as point-charge VDW spheres (only minimization, no MD, and no QM to incorporate orbital directionality). It could be useful modifying existing metal complex structures, and as mentioned above, analyzing those structures output from other programs. I hope this helps, Elaine ---------- Elaine C. Meng, Ph.D. UCSF Computer Graphics Lab (Chimera team) and Babbitt Lab Department of Pharmaceutical Chemistry University of California, San Francisco On Jun 22, 2011, at 11:11 PM, Mickey Branham wrote: > Dr. Meng > Our group is interested in drug-metal complexation modeling. We have ongoing MM and MD studies using Gaussian or COSMO, with mixed results. Before we embark on a new voyage into Chimera can you tell us its capacity for elucidating drug-metal complexes e.g. tetracycline-M+2. > > Cheers > Mickey > > Michael Lee Branham, PhD. > University of KwaZulu-Natal > School of Pharmacy and Pharmacology > Durban, South Africa > > Please find our Email Disclaimer here-->: http://www.ukzn.ac.za/disclaimer > Please find our Email Disclaimer here: http://www.ukzn.ac.za/disclaimer/

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System requirements
by יוכבד 04 Jul '11

04 Jul '11

Hi I'm looking into upgrading my computer and I was wondering whether Chimera runs properly on Windows7 and with a NVIDIA GT430 1GB graphic card. Thank you Yocheved

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Coordinates
by George Tzotzos 01 Jul '11

01 Jul '11

Hi everybody, Is there a way to find out the coordinates of the centre of mass of (a) protein; (b) a specific residue in a protein; (c) a ligand bound on a protein. I searched the Chimera documentation but didn't find anything appropriate. Maybe that my search terms were wrong. Many thanks and best regards George

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Chimera-users July 2011