A pairwise Born potential connecting the heavy atom sites within a prescribed cutoff, and the equation of motion method (EOM), reproduce the existence of a universal singularity in the low-frequency vibrational density of states of typical globular proteins. This is due to quasilocalization of acoustic waves and an analogy with a similar feature found in glasses is stressed. We explain the dependence of this anomaly with the effective dimensionality of the protein. The EOM method allows for the study of even the largest proteins with a simple personal computer.