FightAIDS@home, поиск лекарств от ВИЧ и СПИДа Налаштування

[Rilian]

Проект занимается подбором лекарств от ВИЧ

* Официальный сайт
* Прогресс и статус исследований на официальном сайте

Как присоединиться читайте в главном топике World Community Grid

Подробнее о научных методах в FightAIDS@Home:

Белки, как вы уже знаете, является строительным материалом для всех живых существ. Разнообразные формы белков принимают участие во всех процессах, происходящих в живых организмах. Белки являются длинными цепями меньших молекул - аминокислот.

Энзимы являются конкретными типами белков, которые ускоряют биохимические реакции.

Протеаза - энзим, который способен «вырезать» отдельный белок в некоторой точке аминокислотной цепи. Например, когда Вы едите пищу, которая также содержит белок, белковые молекулы режутся на меньшие аминокислотные молекулы протеазой в вашем желудке.

Ваш организм может затем использовать получившиеся аминокислоты, чтобы формировать белки, которые ему нужны для продолжения жизнедеятельности. Стоит отметить также, что только небольшой процент из всех белков в организме является протеазами, поэтому эти белки очень важны в своем функционировании для обеспечения жизненных процессов.

Ваш компьютер поможет нам имитировать процесс присоединения множества различных лиганд* к HIV-протеазе (HIV- Human Immunodeficiency Virus – вирус иммунодефицита человека), для этого используется компьютерная программы под названием AutoDock.

*Лиганды - (от лат . ligo - связываю), в комплексных соединениях молекулы или ионы, связанные с центральным атомом (комплексообразователем), напр. в соединении [Co(NH3)6]Cl3 центральный атом - Со, а лиганды - молекулы NH3.

Перспективные лиганды будут изучены более подробно учеными, и это должно привести нас к созданию лекарства для управления ВИЧ-инфекцией, и в конце концов, к предотвращению заболевания СПИДОМ.

Естественно, моделирование таких процессов – сложная в вычислительном отношении задача из-за большого разнообразия белковых структур и выделению из них тех, которые могут эффективно повлиять на вирус, поэтому в данном проекте также используются методы распределенных вычислений.

What is AIDS?
UNAIDS, the Joint United Nations Program on HIV/AIDS, estimated that in 2004 there were more than 40 million people around the world living with HIV, the Human Immunodeficiency Virus. The virus has affected the lives of men, women and children all over the world. Currently, there is no cure in sight, only treatment with a variety of drugs.

Prof. Arthur J. Olson's laboratory at The Scripps Research Institute (TSRI) is studying computational ways to design new anti-HIV drugs based on molecular structure. It has been demonstrated repeatedly that the function of a molecule — a substance made up of many atoms — is related to its three-dimensional shape. Olson's target is HIV protease ("pro-tee-ace"), a key molecular machine of the virus that when blocked stops the virus from maturing. These blockers, known as "protease inhibitors", are thus a way of avoiding the onset of AIDS and prolonging life. The Olson Laboratory is using computational methods to identify new candidate drugs that have the right shape and chemical characteristics to block HIV protease. This general approach is called "Structure-Based Drug Design", and according to the National Institutes of Health's National Institute of General Medical Sciences, it has already had a dramatic effect on the lives of people living with AIDS.

Even more challenging, HIV is a "sloppy copier," so it is constantly evolving new variants, some of which are resistant to current drugs. It is therefore vital that scientists continue their search for new and better drugs to combat this moving target.

Scientists are able to determine by experiment the shapes of a protein and of a drug separately, but not always for the two together. If scientists knew how a drug molecule fit inside the active site of its target protein, chemists could see how they could design even better drugs that would be more potent than existing drugs.

To address these challenges, World Community Grid's FightAIDS@Home project runs a software program called AutoDock developed in Prof. Olson's laboratory. AutoDock is a suite of tools that predicts how small molecules, such as drug candidates, might bind or "dock" to a receptor of known 3D structure. The very first version of AutoDock was written in the Olson Laboratory in 1990 by Dr. David S. Goodsell, since then, newer versions, developed by Dr. Garrett M. Morris, have been released which add new scientific understanding and strategies to AutoDock, making it computationally more robust, faster, and easier for other scientists to use. From the beginning of this project, World Community Grid has been running a pre-release version of AutoDock4. In August 2007, World Community Grid started running the new publicly available version 4 of AutoDock which is faster, more accurate, can handle flexible target molecules and thus can also be used for protein-protein docking analysis. AutoDock is used in the FightAIDS@Home project on World Community Grid to dock large numbers of different small molecules to HIV protease, so the best molecules can be found computationally, selected and tested in the laboratory for efficacy against the HIV virus. By joining forces together, The Scripps Research Institute, World Community Grid and its growing volunteer force can find better treatments much faster than ever before.

График проекта


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ВИЧ 3D

Це повідомлення відредагував Rilian: Sep 8 2010, 11:49

[Rilian]

Project Status, as of December 12, 2011

Experiment 39: 0% Completed

Experiment 39 involves screening the Enamine library of 2,345,014 compounds against the newly-discovered allosteric binding site on HIV-1 integrase. This new allosteric binding site (which we are also targeting in Experiment 38) was discovered by Professor John J. Deadman's group, and it was described in "Structural basis for a new mechanism of inhibition of HIV-1 integrase identified by fragment screening and structure-based design," by D.I. Rhodes, T.S. Peat, J.J. Deadman, et al., published in the journal Antiviral Chemistry and Chemotherapy, 21: 155-168 (2011). The new crystal structure from this paper that contains the atomically-detailed, 3-D data on this new allosteric site is called "3NF6.pdb". We are screening compounds against this allosteric site to try to discover new, larger, more potent allosteric inhibitors of HIV-1 integrase. It is hoped that these new allosteric inhibitors of integrase will be effective at disabling the current drug-resistant mutant superbugs of HIV integrase. For more information about this new allosteric site, see Volume 10 of the FightAIDS@Home newsletter or our recent World AIDS Day webinar (both are linked at the top of the homepage for this site).

In Experiment 39, we are screening these 2.3 million compounds against the new allosteric site on HIV-1 integrase using two slightly different docking approaches: in the first half of these calculations, we are using the smaller dimensions of the "grid box" (the region that the compounds are allowed to explore during the docking calculations) that produced the best results in the "positive control" docking calculations that reproduced the known binding mode of this new allosteric fragment (see the figures in Volume 10 of the FAAH Newsletter, page 8). In the second half of these calculations, we are using a larger grid box, to try to find even larger allosteric inhibitors that can bind strongly with both the allosteric site and other sub-pockets that are adjacent to it.


This experiment involves faah26,811 - faah31,500.

These calculations have not yet begun.


Experiment 38: 31% Completed

Experiment 38 involves screening the full NCI library of 316,179 compounds against the newly-discovered allosteric binding site on HIV-1 integrase. This new allosteric binding site was discovered by Professor John J. Deadman's group, and it was described in "Structural basis for a new mechanism of inhibition of HIV-1 integrase identified by fragment screening and structure-based design," by D.I. Rhodes, T.S. Peat, J.J. Deadman, et al., published in the journal Antiviral Chemistry and Chemotherapy, 21: 155-168 (2011). The new crystal structure from this paper that contains the atomically-detailed, 3-D data on this new allosteric site is called "3NF6.pdb". We are screening compounds against this allosteric site to try to discover new, larger, more potent allosteric inhibitors of HIV-1 integrase. It is hoped that these new allosteric inhibitors of integrase will be effective at disabling the current drug-resistant mutant superbugs of HIV integrase. For more information about this new allosteric site, see Volume 10 of the FightAIDS@Home newsletter (pages 7-8) or our recent World AIDS Day webinar (both are linked at the top of the homepage for this site).


This experiment involves faah26,179 - faah26,810.

These calculations began 12/06/2011.


Experiment 37: 99% Completed

Experiment 37 involves screening the newly-updated version of the Asinex library of 360,00 compounds. 507,000 different models are used to represent these 360,000 compounds (due to the need to represent different protonation states and different tautomers that some of these compounds can form in solution). These compounds are being screened against the active site and the "eye site" of 6 different crystal structures of HIV protease. When the flaps have a semi-open conformation, then we can target both the "eye site" and the floor of the active site. But when the flaps have a closed conformation, the "eye site" is no longer accessible (which means that we will only target the traditional active site, which is where the current HIV protease drugs bind).

The 1st target is the crystal structure of the wild type HIV protease with 5-nitroindole bound in the eye site. This new crystal structure from Prof. C. David Stout's lab was presented in the Supporting Information for our recent article in Chemical Biology and Drug Design, vol. 75: 257-268 (March 2010). Since this crystallographic structure has semi-open flaps, we are screening these compounds against both the eye site and the active site of this target.

The 2nd target is the semi-open crystal structure of wild type HIV-1b protease from 1HHP.pdb. This crystal structure has been used in previous virtual screens that were performed by Prof. Heather Carlson's group, in which they did find a novel inhibitor of HIV protease activity. Thus, this particular crystal structure has already been proven to be useful for virtual screens that target the "eye site." The idea of targeting this eye site was first proposed by Prof. Heather Carlson's group. But in this experiment, we are screening different compounds against this crystal structure than the compounds that were used in previous screens against 1HHP.pdb.

The 3rd target has only been used in one previous FightAIDS@Home experiment (i.e., Experiment 35). It is a brand new crystal structure from Assoc. Prof. C. David Stout's lab of the chimeric "FIV 6s98S" protease, which was developed by our collaborators Ying-Chuan Lin, Prof. Bruce E. Torbett, and Prof. John H. Elder, and which has a closed conformation of the flaps. A paper on this new crystal structure of FIV 6s98S protease was recently accepted for publication in Acta Crystallographica and can be found at the above link. This protease enzyme is "chimeric," because it contains 5 residues from HIV protease that were substituted into the corresponding positions in FIV protease. The 6th residue was also substituted from HIV protease, but it changed into a different residue during serial passage experiments (i.e., during directed evolution studies). This 6s98S FIV protease has HIV-like drug sensitivity profiles and is a new model system for multi-drug-resistant HIV protease.

The 4th target is the crystal structure of wild type HIV-1b protease bound to the drug darunavir. This crystal structure from 2IEN.pdb has a closed conformation of the flaps. Whenever we target a crystal structure of HIV protease that has a compound bound to it, we delete that ligand before we prepare the model of the target for these docking studies (so that a new compound might be able to bind in its place).

The 5th target is the crystal structure of wild type HIV-1b protease bound to the compound TL-3 and to the allosteric fragment "4d9". This crystal structure, which has closed flaps, was also from the 2010 Chemical Biology & Drug Design paper cited above.

The 6th target is the crystal structure of the V82F/I84V multi-drug-resistant mutant (or "superbug") of HIV protease from 1MSN.pdb, which has closed flaps. The model of this target has one protonated aspartic acid 25 (i.e., one of the two catalytic residues), which should cause us to fish out slightly different types of ligands.

The 7th target is another version of the semi-open crystal structure of wild type HIV-1b protease from 1HHP.pdb. That is, this is the same molecule as the 2nd target in this experiment, but this time the model has one protonated aspartic acid 25.


This experiment involves faah22,630 - faah26,178.

These calculations began 5/12/2011.