Re: [AMBER] non-bonded parameters for ferric iron and ferrous iron

From: Jean-Paul Becker <jpb.q4md-forcefieldtools.org>
Date: Thu, 06 Mar 2014 15:47:14 +0100

Hi Pengfei,

It will certainly not surprise you that one of my major concern is time.
It seems that between the parametrization and the availability of
the potential in Amber14, it can be within more than a couple of
months from now.
My dynamics are currently running with the 'old' parameters and I
would have liked
to have the opportunity to assess your development right away.
I will be glad if you can send the parameters to me as soon as you get them.
By the way, with your agreement, they can be a great addition to the RED DB.

Cheers.
JPB.



Pengfei Li <ambermailpengfei.gmail.com> a écrit :

> Hi Jean-Peul,
>
> The 12-6-4 model has been added to Amber 14 as a new feature which will be
> released in the coming April. For the Fe3+ ion, the 12-6-4 parameterization
> work is undergoing in our group. Since there are also other projects
> undergoing, it may take some time for us to get it (and if you are
> interested in, we can send you the parameter after we get it). Hope this
> helps, if you have more questions or concerns, please tell me.
>
> All the best,
> Pengfei
>
>
>
>
> 2014-03-05 16:11 GMT-05:00 Jean-Paul Becker <jpb.q4md-forcefieldtools.org>:
>
>>
>>
>> ----- Message transféré de jean-paul.becker.u-picardie.fr -----
>> Date : Wed, 05 Mar 2014 20:32:24 +0100
>> De : Jean-Paul Becker <jean-paul.becker.u-picardie.fr>
>> Objet : Re: [AMBER] non-bonded parameters for ferric iron and ferrous
>> iron
>> À : AMBER Mailing List <amber.ambermd.org>, Ken Merz <
>> kmerz1.gmail.com>
>> Cc : Pengfei Li <ldsoar1990.gmail.com>
>>
>> Hi Kennie,
>>
>> Thanks for the answer.
>> Regarding the topology of the bonded model we took advantage of our
>> RED server and especialy its new version written in Python.
>> However, I would be very curions and interested to use your LJ params
>> for trivalent cations (ferric iron) on our model and évaluate how they
>> perform.
>> Right now, I am not sure which way to proceed, I don't know how much
>> it implies
>> to use 12-6-4 model within Amber.
>> Cheers.
>> JPB
>>
>> Ken Merz <kmerz1.gmail.com> a écrit :
>>
>> > Hi,
>> > We created LJ params for the ferrous iron, but not ferric
>> > (http://pubs.acs.org/doi/abs/10.1021/ct400146w and
>> >
>> http://pubs.acs.org/doi/abs/10.1021/ct400751u?prevSearch=pengfei%2Bli&searchHistoryKey=).
>> We might be willing to create these for you if you are dissatisfied with
>> what is out there. We can create a 12-6 or a 12-6-4 model depending on how
>> you want to proceed. To create a bonded model for the coordination
>> environment you can use MCPB. Good luck,
>> > Kennie
>> >
>> > On Mar 4, 2014, at 12:08 PM, Jean-Paul Becker
>> > <jpb.q4md-forcefieldtools.org> wrote:
>> >
>> >> Dear Amber users,
>> >>
>> >> I searched the bibbliography for non-bonded parameters for
>> >> a five-coordinate ferric iron.
>> >>
>> >> There are the well known values coming from D.A. Giammona's PhD
>> >> thesis (1.2 and 0.05)
>> >> that were once in the Amber contrib but removed recently.
>> >> These values are said to be appropriate for a six-coordinate iron
>> though.
>> >>
>> >> In the supporting information of Shahrokh et al. (J. Comput. Chem.
>> >> 33:119-133,2012)
>> >> one can find three sets of non-bonded parameters either for ferrous
>> iron or
>> >> ferric iron in different environment:
>> >> 1.8 0.01
>> >> 1.3 0.002
>> >> 1.3 0.01
>> >> but reading the paper, the method used to derive these parameters does
>> >> not appear clearly.
>> >>
>> >> In Shahrokh et al., a reference leads to Moore et al.
>> >> (Biochemistry 49:9011-9019,1010) where one can read:
>> >> "The van der Waals parameters for the heme iron atom were manually
>> >> assigne Rii
>> >> and epsii values of 1.3 and 0.01, respectively."...
>> >>
>> >> I am wondering where to look for published and trustworthy non-bonded
>> >> parameteres suitable
>> >> to ferric iron in a five-coordinate environment.
>> >> My question is also more general and applies to ferrous and ferric
>> >> iron in five-coodinate
>> >> and six-coordinates environmants as well.
>> >> Any suggestion would be deeply appreciated.
>> >>
>> >> Cheers.
>> >> JPB.
>> >>



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Received on Thu Mar 06 2014 - 07:00:03 PST
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