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Inconsistent IDs for FMN and FMNH2

Open Devlin-Moyer opened this issue 2 years ago • 4 comments

Current behavior:

I was starting to work on implementing the changes I proposed in #609, and I noticed inconsistencies in the metabolite IDs for FMN and FMNH2 metabolites in different compartments:

ID Name Compartment Formula Charge
MAM01828c FMN c C17H19N4O9P -2
MAM01828x FMN x C17H19N4O9P -2
MAM01828e FMN e C17H19N4O9P -2
MAM20020r FMN r C17H18N4O9P -2
MAM20023i FMN i C17H18N4O9P -2
MAM20019r FMNH2 r C17H21N4O9P -2
MAM20022i FMNH2 i C17H21N4O9P -2

(These are all of the metabolites currently in Human-GEM that have "FMN" in their names. Also I bolded the number of hydrogens in the empricial formulas just to make it clear that that's the only part that changes)

Expected feature/value/output:

  • [X] All of the FMN metabolites should have the same IDs except for the compartment suffix, so MAM20020r should be MAM01828r and MAM20023i should be MAM01828i.
  • [X] Same for the FMNH2 metabolites: MAM20022i should be MAM20019i.
  • [X] The empirical formulas for all FMN metabolites should be the same. According to ChEBI, PubChem, and KEGG, the formula for (neutral) FMN should be C17H21N4O9P, and since these represent the -2 ion of FMN, the formulas for MAM20020r and MAM20023i should be changed to C17H19N4O9P.
  • [X] All of the FMN metabolites should be associated with the same KEGG ID, so MAM20020r and MAM20023i should both be associated with C00061.
  • [X] Relatedly, neither of the FMNH2 metabolites are currently associated with a KEGG ID, so they can both be associated with C01847.

Devlin-Moyer avatar Oct 20 '23 17:10 Devlin-Moyer

thanks for the scrutiny, go ahead to implementation please

haowang-bioinfo avatar Oct 20 '23 17:10 haowang-bioinfo

FYI I just edited my proposed changes a bit because I realized the empirical formulas I looked up were for neutral FMN and FMNH2, but these metabolites represent their -2 ions since their phosphate groups deprotonate in water at physiological pHs.

Devlin-Moyer avatar Oct 20 '23 17:10 Devlin-Moyer

yes, KEGG often picks neutral state for metabolites - in fact the protonation state under pH 7.3 is favoured

haowang-bioinfo avatar Oct 20 '23 17:10 haowang-bioinfo

let's keep this issue open until the charge-balancing fixed

haowang-bioinfo avatar Oct 23 '23 21:10 haowang-bioinfo