Hi David,

The link to the data has now expired, Let me know if you are still willing 
to have a look and I can send it again.

Otherwise maybe you could briefly describe the process you would go through?

Many thanks,
Alastair

On Thursday, 6 August 2020 22:17:00 UTC+2, Alastair Skeffington wrote:
>
> Hi David,
>
> Many thanks for your reply.
>
> So it any peptides with modifications will simply be ignored for 
> quantification and I can ignore the warning message?
>
> Yes - each search was either light or heavy as defined in the static 
> modifications. 
>
> And the -r parameter is then the window to search in the RT dimension? 
> Because the command line option says 'range around precursor m/z to search 
> for peak' I assumed this was for the m/z dimension. I thought that the 
> shift of the peak would also mostly be in the m/z dimension - but I'm no 
> mass spectrometrist!
>
> I would be amazing if you had a moment to have a look at the data - thanks 
> very much for offering. I've put two example pairs of files here: 
> https://we.tl/t-cVDD1MVDOr 
>
> For each sample there is a light 'L' version of the search results and a 
> heavy 'H' version. I've also included the search database (based on some 
> PacBio data some I'm afraid it's quite big with a lot of isoforms).
>
> Many thanks,
> Alastair
>
> On Wednesday, 5 August 2020 20:37:16 UTC+2, David Shteynberg wrote:
>>
>> Hi Alastair,
>>
>> If your search results are either all heavy or all light (not variable 
>> mod searched) then you should also use option -S.  
>>
>> 1). You cannot specify anything but single amino acids in this string.  
>> Your quantitation will be based on peptides without PTMs in this dataset.
>>
>> 2). -r8 is a MUCH too wide window to recover the MS1 signal in RTspace.  
>> The lower this number the more selective the tool is at isolating your 
>> target signal.  With -r8 you will not be quantifying the correct signal, 
>> unless you have a very bare sample.
>>
>> If you are able to share this data I can try running it to help you 
>> optimize your settings.
>>
>> Thanks,
>> -David
>>
>> On Wed, Aug 5, 2020 at 11:02 AM 'Alastair Skeffington' via 
>> spctools-discuss <[email protected]> wrote:
>>
>>> Hello,
>>>
>>> I'm trying to run a 14N/15N labelling experiment through ASAPRatio. I've 
>>> been running the first steps like this - here for the results of a database 
>>> search with heavy masses:
>>>
>>> InteractParser sample_interact.pep.xml sample.pep.xml
>>>
>>> PeptideProphetParser sample_interact.pep.xml
>>>
>>> RefreshParser sample_interact.pep.xml ./EhuxAllproteins_MCC_decoy.fasta
>>>
>>> ASAPRatioPeptideParser sample_interact.pep.xml  -lACDEFGHIKLMNPQRSTVWY 
>>> -r8 
>>> -mA72.0779R160.1857N116.1026D116.0874C104.1429E130.1140Q130.1292G58.0513H140.1393I114.1576L114.1576K130.1723M132.1961F148.1739P99.1152S89.0773T102.1038W188.0793Y164.0633V101.1311
>>>
>>> At this point I get a warning:
>>>
>>> WARNING: Found more than one variable mod on 'M'. Please make sure to 
>>> specify a heavy mass for this residue
>>>
>>> So I have two questions:
>>>
>>> 1) How do I specify the heavy mass for oxidised methionine? Mox ? And is 
>>> phosphorylated serine coded Sp ?
>>>
>>> 2) I've used -r8 instead of the default 0.5. My reasoning is that a 
>>> medium sized heavy peptide could easily differ from the 14N counterpart by 
>>> 16 Da. Assuming charge +2, then using a m/z range of 8. Does this sound 
>>> remotely sensible?
>>>
>>> Many thanks!
>>> Alastair
>>>
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>>>
>>

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