Protein Wonderland

(To the tune of “Winter Wonderland”)

Mechan-i-sm . . determines
How an en . . zyme is workin’
Here are the ways
That each elastase
Breaks a peptide bond so easily

Starting with the binding of the substrate
Catalytic triad is the star
Histidine’s electron sink reacts to
Pull a proton from a serine’s a-r-r-r-r

Then the al . . . koxide ion
Gets elec . . . trons a-flyin
It makes a big fuss
For one nuc-le-us
And breaks and makes a bond with carbonyl

Then the process switches in its action
Water comes to free the carbonyl
Loss of proton yields hydroxide ion
Attacking on the peptide bound there still -ll -ll

Which the en . . . . zyme releases
Otherwise . . . action ceases
The process is done
Until the S1
Binds a substrate starting up again