Аннотация:Using the method of dynamic light scattering, it was found that the rate of collagen cleavage under the influence of bacterial collagenase decreases by almost 4 times when protein molecules are doped with Cr3+ ions, and when the enzyme activator of Zn2+ ions is added, it increases by 1.3 times. Based on the experimental data, the reaction rate constants k1 were calculated. It was found that when collagen molecules are tanned with a chromium salt, it becomes more resistant to degradation in solutions containing zinc ions than in solutions with the addition of calcium ions, as we described in earlier works. Keywords: collagen type 1, bacterial collagenase, chromium chloride, zinc chloride, dynamic light scattering method, translational diffusion coefficient, hydrodynamic radius, reaction rate constant, collagenolysis, Clostridium histolyticum.