Last couple to sharpen axes with me - a catalyst for change (6)
I believe the answer is:
enzyme
'me a catalyst for change' is the definition.
I can't judge whether this definition defines the answer.
'last couple to sharpen axes with' is the wordplay.
'last' indicates one should take the final letters.
'axes with' becomes 'zyme' (I can't justify this - if you can you should give a lot more credence to this answer).
The final letters of 'couple sharpen' are 'en'.
'en'+'zyme'='ENZYME'
Can you help me to learn more?
(Other definitions for enzyme that I've seen before include "Protein product of living cells" , "Catalytic protein substance" , "Protein substance acting as a catalyst" , "Catalyst made of protein" , "E.g. pepsin" .)