#13 Is 1,4-dithiothreitol really a cofactor in 5.4.3.5?

closed
nobody
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5
2011-02-23
2008-05-22
No

IntEnz entry 5.4.3.5 has 3 cofactors listed. The two references support that PLP and B12 are cofactors for this reation, however, neither of the two references claims that 1,4-dithiothreitol is a cofactor in this reaction. The 1973 reference only says:

"However, about 75% of maximal activity was recovered
in the absence of dithiothreitol if oxygen was depleted by gassing with argon. Dithiothreitol completely replaced the anaerobic requirement achieved with argon. Presumably, the mercaptan functions to keep essential, labile sulfhydryl groups reduced and protected from oxygen, or also protects coenzyme B12 from oxidation during the catalytic process."

This statement doesn't even claim that DTT is present in vivo.

Also the second reference only mentions DTT as part of the buffer. If this is the only evidence for DTT to be a cofactor, I suggest to remove it from the cofactor list.

My preliminary database research shows that only this reaction is lists DTT as a cofactor. If this turns out to be confirmed, you might want to reconsider DTT's classification as a cofactor in ChEBI as well.

Discussion

  • Kristian Axelsen

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    Dear Julia,

    You are right once again. I will remove it immediately.

    As always thank you for these error reports. They are very helpful.

    Regards,

    Kristian

     
  • Rafael Alcántara

    • status: open --> closed
     
  • Rafael Alcántara

    Fixed long ago. Thanks!

     

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