Binding interactions of pefloxacin mesylate with bovine lactoferrin and human serum albumin

The binding of pefloxacin mesylate （PFLX） to bovine lactoferrin （BLf） and human serum albumin （HSA） in dilute aqueous solution was studied using fluorescence spectra and absorbance spectra. The binding constant K and the binding sites n were obtained by fluorescence quenching method. The binding distance r and energy-transfer efficiency E between pefloxacin mesylate and bovine lactoferrin as well as human serum albumin were also obtained according to the mechanism of Forster-type dipole-dipole nonradiative energy-transfer. The effects of pefloxacin mesylate on the conformations of bovine lactoferrin and human serum albumin were also analyzed using synchronous fluorescence spectroscopy.

Heterologous expression of bovine lactoferrin C‑lobe in Bacillus subtilis and comparison of its antibacterial activity with N‑lobe

The natural concentration of bovine lactoferrin C-lobe is low and its separation by proteolytic enzyme digestion is difcult.Here,we expressed the codon-optimized fragment of C-lobe on plasmid pMA0911 with the P_(veg) promoter in Bacillus subtilis 168 at 20℃.The yield was 7.5 mg/L,and 90.6%purity was achieved using ammonium sulfate precipitation,Ni–NTA and molecular exclusion.The C-lobe at 10 mg/mL completely inhibited cell growth of Escherichia coli JM109(DE3)and Pseudomonas aeruginosa CGMCC 1.6740,and 48.4%of growth of Staphylococcus aureus CGMCC 1.282,the result is similar to that of 200 ng/mL N-lobe.The minimum inhibitory concentrations of C-lobe were 4,8 and 16 mg/mL,while those of N-lobe were 128,256 and 512μg/mL for E.coli,P.aeruginosa and S.aureus,respectively.This is the frst report on bovine lactoferrin C-lobe expression and the comparative resistance of the recombinant N-and C-lobes in a food-safe strain of B.subtilis.Our fndings ofer the potential to study the structure–function relationship of the N-and C-lobes recombinantly produced in the same host.

Efficacy of fermented milk and whey proteins in Helicobacter pylori eradication:A review

Helicobacter pylori (H. pylori) eradication is considered a necessary step in the management of peptic ulcer disease, chronic gastritis, gastric adenocarcinoma and mucosa associated lymphoid tissue lymphoma. Standard triple therapy eradication regimens are inconvenient and achieve unpredictable and often poor results. Eradication rates are decreasing over time with increase in antibiotic resistance. Fermented milk and several of its component whey proteins have emerged as candidates for complementary therapy. In this context the current review seeks to summarize the current evidence available on their role in H. pylori eradication. Pertinent narrative/systematic reviews, clinical trials and laboratory studies on individual components including fermented milk, yogurt, whey proteins, lactoferrin, α-lactalbumin (α-LA), glycomacropeptide and immunoglobulin were comprehensively searched and retrieved from Medline, Embase, Scopus, Cochrane Controlled Trials Register and abstracts/proceedings of conferences up to May 2013. A preponderance of the evidence available on fermented milk-based probiotic preparations and bovine lactoferrin suggests a beneficial effect in Helicobacter eradication. Evidence for α-LA and immunoglobulins is promising while that for glycomacropeptide is preliminary and requires substantiation. The magnitude of the potential benefit documented so far is small and the precise clinical settings are ill defined. This restricts the potential use of this group as a complementary therapy in a nutraceutical setting hinging on better patient acceptability/compliance. Further work is necessary to identify the optimal substrate, fermentation process, dose and the ideal clinical setting (prevention/treatment, first line therapy/recurrence, symptomatic/asymptomatic, gastritis/ulcer diseases etc.). The potential of this group in high antibiotic resistance or treatment failure settings presents interesting possibilities and deserves further exploration.