  ${\bf Background}$ Details of the kinetic pathways governing enzymatic
cleavage of hyaluronic acid (HA) by hyaluronidase are still widely uncharted.
Capillary electrophoresis-based assays were used for accurate quantification of
enzymatic products. A crowding agent was also employed to mimic excluded-volume
constraints typical of in-vivo conditions.
  $ {\bf Scope}$ Introduce a comprehensive kinetic model describing the
late-stage degradation of HA by hyaluronidase and identify the relevant kinetic
pathways and the associated rates.
  ${\bf Major Conclusions}$ All relevant fragmentation and transglycosylation
pathways and rates were identified. Two dimers forming a tetramer is the
dominant recombination pathway. Macromolecular and self-crowding slow down the
kinetics but do not alter the underlying mechanisms.
  ${\bf General Significance}$ Our results bring a novel and comprehensive
quantitative insight into enzymatic HA degradation. Rationalizing the effect of
crowding brings the intricate conditions of in-vivo settings a little closer,
and also stands as a powerful tool to pinpoint relevant kinetic pathways in
complex systems.
