Re: [AMBER] about VMD's molecular surface area calculation

From: Balazs Jojart <jojartb.gmail.com>
Date: Wed, 05 May 2010 10:56:24 +0200

Hi Geyan,
I think you can use the following commands:
set all [atomselect top "protein and nucleic"]
set prot [atomselect top "protein"]
set nucleic [atomselect top "nucleic"]
measure sasa 1.4 $all -restrict $prot
measure sasa 1.4 $all -restrict $nucleic
the first measure will contain only the contribution of the protein, and
the second one the contribution of the nucleic acid to the whole surface.
HTH,
Balazs


geyan wrote:
> Hello Balazs,
> With your previous reply about the molecular surface area calculation,I write this email to you and hope you can help me.
> Now I meet a abnormal phenomenon.I have a system of DNA-Protein complex.This kind of protein can compass the DNA to protect it from damage.So it's reasonable that the surface area of the DNA is decreasing with the binding of the protein.But with the command in VMD,that is "set dna [atomselect top "dna"] " and "measure sasa 1.4 $dna",the result is opposite to arrise.So can you tell me why the value of the surface area is becoming larger after binding?What I meant to do is to quantify the protection of the protein to DNA by calculating the exact reduction of the surface area of the DNA.
> Thanks advance.
>
>
> 2010-05-05
>
>
>
> geyan
>
>
>
> 发件人: Balazs Jojart
> 发送时间: 2010-04-23 14:28:00
> 收件人: AMBER Mailing List
> 抄送:
> 主题: Re: [AMBER] molecular surface area
>
> Hello Geyan,
> see my previous post about this issue:
> http://archive.ambermd.org/201003/0585.html
> HTH
> Balazs
> geyan wrote:
>
>> Has anybody done this analysis before?
>> I want to focus on the protection of protein to DNA.Now there is a interesting thing,when the DNA is in nature,the surface area is one figure,when the protein bind to it, both the surface area of protein and DNA will change,from which we can measure the protection effect.
>> My question is how to quantify the surface area.which program can do this well and easily?I think amber is powerful enough to figure it out easily,but how?
>> Many thanks.
>>
>> --------------
>> geyan
>> 2010-04-23
>>
>>
>>
>> _______________________________________________
>> AMBER mailing list
>> AMBER.ambermd.org
>> http://lists.ambermd.org/mailman/listinfo/amber
>>
>>
>>
> _______________________________________________
> AMBER mailing list
> AMBER.ambermd.org
> http://lists.ambermd.org/mailman/listinfo/amber
>
> ------------------------------------------------------------------------
>
> _______________________________________________
> AMBER mailing list
> AMBER.ambermd.org
> http://lists.ambermd.org/mailman/listinfo/amber
>


_______________________________________________
AMBER mailing list
AMBER.ambermd.org
http://lists.ambermd.org/mailman/listinfo/amber
Received on Wed May 05 2010 - 02:00:04 PDT
Custom Search