Improving the catalytic performance of Proteinase K from Parengyodontium album for use in feather degradation

Abstract

Proteinase K (PROK) from Parengyodontium album hydrolyzes keratin, a major protein component of poultry feathers, which are an inexpensive and renewable protein resource. Based on structural studies for analysis of amino acid flexibility near the catalytic center, identification of highly conserved residues, and experimental screening, we obtained a mutant R218S with residual activity 1.6-fold higher than that of PROK after incubation at 60 °C for 1 h. Molecular dynamics simulation indicated that substitution of Arg218 with Ser leads to three hydrogen bonds being introduced into the structure, stabilizing the β-sheet in which Ser218 is located, and thus improvement of thermostability. Additionally, the mutant R218S had a 15% increase in specific activity compared to PROK and improvement in the rate and thoroughness of feather degradation compared with PROK. We confirmed the positive effects of enhancing catalytic center rigidity on enzyme thermostability, a finding which may have broad applications.

A Novel Thermostable Keratinase from Deinococcus geothermalis with Potential Application in Feather Degradation

“…As shown in Figure 4, DgeKer and DgeKer-C exhibited maximal activity at 70 • C, which was higher than most of the other keratinases [18,32], such as KerA-derived (50 • C) [30] and MtaKer (65 • C) [11]. In terms of thermostability, DgeKer-C performed better than DgeKer (Figure 4).…”

“…Chicken feathers degradation was carried out according to Yaxin Ren [18] with some modifications. Chicken feather was previously washed and cleaned with detergent and tap water, followed by soaking in 70% ethanol for 1 h and drying.…”

Growth and survivability of the black carpet beetle fed a whole feather diet

“…This study shows that digestive enzymes of the black carpet beetle exhibit proteolytic and keratinolytic activity that rivals that of a solution of commercial Proteinase K at a working concentration of 1mg/ml which is 5–10 times the normal working concentration for proteolysis (50–250 µg/ml) (Ren et al., 2020). Furthermore, it shows that these enzymes are functional at nearly room temperature conditions, and neutral pH, which makes them ideal for maximizing sustainability during large scale applications.…”

Production of Plant Proteases and New Biotechnological Applications: An Updated Review

“…The preliminary data reported indicated that plant proteases are suitable to be applied in combination with other enzymes (trypsin and proteinase K) to achieve feasible yields in keratin degradation has been reported. [159]…”