trypsin cleavage in organic odyssey?

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humcar22

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Trypsin cleaves on the carboxy side of Lys and Arg...

so I'm wondering why when the sequence Ala-Val-Lys-Pro-Pro-Ser-Arg-Arg-Val-Pro is cleaved by trypsin, the result is:

Ala-Val-Lys + Pro-Pro-Ser-Arg + Arg-Val-Pro

why is the Arg-Val bond not also cleaved? please help D:

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My understanding is that when the carboxy end is bound to proline, the cleavage does not occur.

That would explain your question, but disagrees with the cleavage of the first segment in your question (Lys/Pro cleavage). Are you sure the fourth residue in that peptide is proline? Or else maybe there is another exception I don't know.
 
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My understanding is that when the carboxy end is bound to proline, the cleavage does not occur.

That would explain your question, but disagrees with the cleavage of the first segment in your question (Lys/Pro cleavage). Are you sure the fourth residue in that peptide is proline? Or else maybe there is another exception I don't know.

This doesn't answer the question as to why Arg/Val bond isn't cleaved.

Cleavage can happen before proline: Does trypsin cut before proline? - PubMed - NCBI

Trypsin cleaves on the carboxy side of Lys and Arg...

so I'm wondering why when the sequence Ala-Val-Lys-Pro-Pro-Ser-Arg-Arg-Val-Pro is cleaved by trypsin, the result is:

Ala-Val-Lys + Pro-Pro-Ser-Arg + Arg-Val-Pro

why is the Arg-Val bond not also cleaved? please help D:

The reason why trypsin cleaved at carboxy side of arginine and lysine is that the catalytic site of trypsin has an aspartate residue whose negative charge can attract and stabilize the positive charges of arginine and lysine (histidine has only a partial positive charge at physiological pH). I don't know of any reason or exception behind why arginine-valine bond isn't cleaved. It's probably an error.
 
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