S, methicillin-sensitive VBIT-4 Protocol Staphylococcus aureus, and Escherichia coli (ESBLs). Even so, DNQX disodium salt web Al-crus 7 only inhibited Micrococcus luteus, Bacillus subtilis, methicillin-sensitive Staphylococcus aureus, and Escherichia coli (ESBLs). By contrast, Al-crus 7 inhibited imipenem-resistant Acinetobacter baumannii with MIC50 of 12 . The diversity of antimicrobial peptides and their functions are associated with the host’s response to different pathogenic bacteria plus the adjustment of symbiotic flora. For Crustins, the sequence feature contained at least one particular WAP domain at their Cterminus. This domain has eight cysteine residues inside a conserved arrangement that forms a tightly packed structure, described on PROSITE as a four-disulfide core (4DSC). Preceding studies suggest that the antibacterial activity of Crustins is associated with the WAP domain. Comparing CruFc with all the WAP domain from Fenneropenaeus chinensis, which produces powerful antibacterial activity against Gram-positive bacteria, CshFc with no the WAP domain has almost no antibacterial activity . After mutating the eight Cys residues within the WAP domain of rCrus1 in the deep-sea hydrothermal vent, none of the mutants exhibited bactericidal activity in the minimum bactericidal concentration of rCrus2 . These benefits supported the viewpoint that the WAP domain is very important for the antibacterial activities of Crustins. Nevertheless, no published report has shown regardless of whether the WAP domain is adequate for Crustins to carry out their activities. This study synthesized two peptides, Al-crusWAP three and Al-crusWAP 7, derived from Al-crus 3 and Al-crus 7, with only the WAP domain. Aside from Micrococcus luteus and Bacillus subtilis, Al-crusWAP 3 displayed effects against Staphylococcus aureus, methicillin-sensitive Staphylococcus aureus, and Escherichia coli (ESBLs) with larger MIC50 values compared with that of Al-crus three. Also, AlcrusWAP 7 demonstrated the exact same effects on Micrococcus luteus and methicillin-sensitive Staphylococcus aureus, compared with Al-crus 7. Having said that, for Bacillus subtilis and imipenemresistant Acinetobacter baumannii, Al-crusWAP 7 displayed a higher MIC50 value. These final results showed that the two peptides exhibited decrease antibacterial activities than Al-crus three and Al-crus 7, respectively, thus suggesting that other amino acid sequences can contribute with each other using the WAP domain for the observed antibacterial activity. 4. Supplies and Procedures 4.1. Strains, Vectors, Reagents, and Enzymes The bacteria tested in this study, including Micrococcus luteus (NRR00100), Bacillus subtilis (NRR00591), Staphylococcus aureus (NRR01280), and Salmonella sp. (NRR00490), have been obtained from Huayueyang Biotech Co., Ltd., Beijing, China. The drug-resistant bacteria integrated the Gram-positive bacteria, Klebsiella Pneumoniae (ESBLs, extended spectrum beta-lactamases; Shop No. 0244), methicillin-resistant Staphylococcus aureus (MRSA; Shop No. H57), methicillin-sensitive Staphylococcus aureus (Retailer No. G280), Escherichia coli (ESBLs, Shop No. G160); as well as the Gram-negative bacteria, imipenem-sensitive Pseudomonas aeruginosa (Shop No. E248), imipenem-resistant Acinetobacter baumannii (Retailer No. E292), imipenem-sensitive Acinetobacter baumannii (Shop No. H422), Klebsiella Pneumoniae (ESBLs, Shop No. F161), and Escherichia coli (ESBLs, Retailer No. K8). All had been obtained in the Institute of Clinical Pharmacology, Peking University, Beijing, China. The aforementioned bacteria had been kept at -80 C with 20 gl.