How does salinity affect the bonds of an enzyme?
Sodium Chloride is not "polar". It is an ionic compound and dissociates into the respective ions in water (because of the latter's high dielectric constant). 

Hydrogen bonds are similar to of dipole-dipole interactions (van der Waals) but much stronger and are therefore classified as a separate type of bond. However excess salt can lead to ion-dipole interactions (which are stronger than H-bond) that may prevent the formation of the hydrogen bond.

Ions such as Cl - can act as chaotropes (cause disorder)[ref]. K+ is also chaotropic while Na+ is kosmotropic (reduces disorder). However both Na+ and Cl - affect the entropy of water very slightly. So the effect of NaCl should be mostly due to ion-dipole interactions.