Gold nanoclusters protected with bovine serum albumin (AuNC) can be used in multiple biomedical applications through functionalization with two new and bioactive peptides. Both cationic peptides sequences of 17 amino acids in length and the cysteine residue at its C-terminus were designed and synthesized. Peptides were obtained by solid phase synthesis using the Fmoc strategy. Peptides may be coupled via disulfide bonds to AuNC with hydrodynamic size ~ 2 nm ± 0.3 determined by dynamic light scattering and it had a zeta potential value equal to − 42 mV. Peptides named NBC2253 and NBC2254 were attached to the AuNC using N-succinimidyl-3-(2-pyridyl-dithiol) propionate as crosslinker agent. AuNC@NBC2253 was more active against methicillin-resistant Staphylococcus aureus (MIC50 6.5 µM) and AuNC@NBC2254 exhibited higher antimicrobial activity than the free peptides on Escherichia coli O157:H7 (MIC50 3.5 µM). No hemolysis was detected for any of the peptides. It is evidenced that these antimicrobial peptides conjugated to AuNC serve as promising agents to combat some multi-resistant bacterial strains and that the specific binding of these antimicrobial peptides to gold nanoclusters improves the interaction of these nanostructured systems with the biological target.

中文翻译：

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与金纳米簇结合的新合成肽：针对大肠杆菌O157：H7和耐甲氧西林金黄色葡萄球菌（MRSA）的抗生素活性。

通过用两种新的生物活性肽功能化，可以用牛血清白蛋白（AuNC）保护的金纳米簇可用于多种生物医学应用。设计并合成了长度为17个氨基酸的阳离子肽序列及其C端的半胱氨酸残基。使用Fmoc策略通过固相合成获得肽。肽可以通过二硫键与AuNC偶联，AuNC的流体力学大小约为2 nm±0.3，通过动态光散射测定，其Zeta电位值等于-42 mV。使用N-琥珀酰亚胺基-3-（2-吡啶基-二硫醇）丙酸酯作为交联剂，将名为NBC2253和NBC2254的肽连接到AuNC 。AuNC @ NBC2253对耐甲氧西林的金黄色葡萄球菌更具活性（MIC50 6.5 µM）和AuNC @ NBC2254在大肠杆菌O157：H7（MIC50 3.5 µM）上显示出比游离肽更高的抗菌活性。没有检测到任何肽的溶血。有证据表明，与AuNC缀合的这些抗微生物肽可作为有前途的试剂来对抗某些多抗性细菌菌株，并且这些抗微生物肽与金纳米簇的特异性结合可改善这些纳米结构系统与生物靶标的相互作用。