Drug-resistant bacterial pathogens represent a significant
threat to public health, and a complicated assortment of
factors has combined to stymie antibiotic development and fuel
this growing crisis.1,2 The current situation has prompted a
need for renewed discovery and development of novel
antibacterials; however experience has shown that conventional
chemotherapies are inevitably undermined by rapid evolution
of their target organisms.3 Therefore, to more comprehensively
address this threat, conventional antibiotic discovery and
development strategies need to be complemented by searches
within previously untapped molecular reservoirs.
There is a growing body of evidence that bacteriolytic
enzymes represent a powerful class of novel therapeutic
candidates.4−10 While microbial bacteriocins and phage
endolysins have dominated early work, antibacterial enzymes
of human origin have the advantage of inherent compatibility
with the human immune system. Human lysozyme (hLYZ), an
important component of innate immunity,11 represents one
protein of particular interest. Lysozymes cleave the core β-(1,4)
glycosidic bond in bacterial cell wall peptidoglycan, thereby
causing bacterial lysis and death. Additionally, hLYZ and other
C-type lysozymes manifest noncatalytic modes of action,12,13
which contribute to their broad spectrum antibacterial activity.
The availability of mass produced recombinant hLYZ has
spurred interest in prospective medical applications, and early
studies in rodent models have been encouraging