Aprotinin

Jinhua hams were secured from Jinzi Ham Food Company (Jinhua, Zhejiang, China). Hemin was purchased from Wako Chemicals USA (Richmond, VA, USA). o-Phthalaldehyde (OPA, 99% purity) and tyrosine (≥99%) were secured from J&K Scientific (Beijing, China). 1,1-Diphenyl-2-picrylhydrazyl (DPPH) was sourced from Coolaber Technology Co., Ltd. (Beijing, China). Ferrozine (98% purity) and bovine serum albumin (BSA) were purchased from Solarbio Biotechnology Co., Ltd. (Beijing, China). Aprotinin (titer > 3 TIU/mg) and bacitracin (titer > 60 Units/mg) were bought from Macklin Biochemical Co., Ltd. (Shanghai, China). BHT (>99% purity), lysozyme (≥20,000 U/mg), and formic acid (≥98%, HPLC) were acquired from Aladdin Biochemical Technology Co., Ltd. (Shanghai, China). Ferric-reducing antioxidant power kits, 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS⁺) radical scavenging capacity kits, and glutathione (GSH) were purchased from Beyotime Biotechnology Co., Ltd. (Shanghai, China). Hydroxyl and superoxide anion-free radical scavenging activity kits were sourced from Nanjing Jiancheng Bioengineering Institute (Nanjing, China). Other analytical-grade reagents were purchased from Mall-bio-Biotechnology Co., Ltd. (Nanjing, China). Phe-Ser-Gly-Leu (98% purity) was synthesized by Qiangyao Biotechnology Co., Ltd. (Wuhan, China).

G. livida was collected from Nan Ao Island (116°56′–117°09′ E and 23°23′–23°29′ N). Epiphytes were removed by hand and samples were dried at 25 °C, followed by hot air-drying for further analysis. Alkaline protease (200 U/mg), Protamex (90 U/mg) and neutral protease (100 U/mg) were purchased from Hefei Bomei Biotechnology Co., Ltd. (Hefei, China). Trifluoroacetic acid (TFA), acetonitrile, methanol, cytochrome C (12,400 Da) and aprotinin (6411.24 Da) were bought from Shanghai Macklin Biochemical Co., Ltd. (Shanghai, China). DPPH and L-oxidized glutathione (612.63 Da) were obtained from Sigma Chemical Co. (St. Louis, MO, USA). Bacitracin (1422.69 Da) and reduced glutathione (307.3 Da) were purchased in Guangzhou Qiyun Biotechnology Co., Ltd. (Guangzhou, China). All other chemicals and reagents used were of analytical grade.