Figure 1

Schematic representation and SDS analysis of ClyL. A The novel chimeric lysin ClyL, which is composed of a cysteine- and histidine-dependent amidohydrolase/peptidase (CHAP) catalytic domain (1–165 aa) from the phage lysin LysGH15 and a cell wall-binding domain (CBD) (143–239 aa) from the prophage lysin Lys0859. B SDS‒PAGE of the recombinant chimeric lysin ClyL. M: marker; 1: purified ClyL (34.0 kDa). C–F Effects of metal ions on the antibacterial activity of Lys0859. Different concentrations of Ca²⁺ (C), Mg²⁺ (D), and Zn²⁺ (E) were added to ClyL (50 μg/mL), and then the mixtures were mixed with S. aureus ATCC 29213 at 37 °C for 30 min. E PBS and 5 mM Ca²⁺, Mg²⁺, and Zn²⁺ were added to Lys0859 (50 μg/mL), and the mixtures were mixed with S. aureus ATCC 29213 at 37 °C for 60 min. Significant differences between the PBS groups and the ClyL groups were determined by Student’s t test (*** P < 0.001). Significant differences between the ClyL groups and the ClyL + 5 mM Ca²⁺, ClyL + 5 mM Mg²⁺, and ClyL + 5 mM Zn²⁺ groups were determined by Student’s t test (# P < 0.05, ## P < 0.05). The data are expressed as the mean ± standard deviation (SD).