αs2-casein f(198-222) or f(183-207) [id=CAA0021]

Producer Organism : Native Protein : Production Method :
Cow αs2-casein Synthetic
Activity : Antibacterial
Target Organisms :

Gram-positive: Active against Listeria innocua CECT 910 T, Staphylococcus carnosus CECT 4491T, Enterococcus faecalis CECT 795 at 0.5 mM, Listeria monocytogenes CECT 934 (MIC=0.05 然), Staphylococcus epidermidis CECT 231 (MIC=2.5 然).

Gram-negative: Active against Escherichia coli ATCC 25922, Serratia marcescens CECT 854 at 0.5 mM, Escherichia coli ATCC 25922 (MIC=1.25 然), Salmonella choleraesuis ssp. choleraesuis CECT 4594 (MIC=0.5 然).

Description :
Production method: Synthetic.

Length : 25 Mass (Da): 3 116.76 Common Amino Acids : K
Isolectric Point : 10.65 Net Charge : 6 Absent Amino Acids : CDEFGNS
Basic Residues : 6 Acidic Residues : 0 Hydrophobic Residues : 8
Polar Residues : 4 Boman Index : -28.02 Hydropathy Index : -0.6
Aliphatic Index : 85.6 Instability Index : 0 Extinction Coefficient : 9970
Absorbance 280nm : 415.42

Wheel representation

Hydrophobicity plot

Red solid plot : values according to the hydrophobicity scale of Kyte and Doolittle (reference paper).
Yellow dashed plot : Experimentally determined hydrophobicity scale for proteins at membrane interfaces(reference paper).
Green dotted-dashed plot : prediction of transmembrane helices (reference paper). In this scale (unlike the others), more negative values reflect greater hydrophobicity.

Multiple Sequence Alignment (MSA)

 2 CAA0020   100.0%  ---------------------------------VYQHQKAMKPWIQPKTKVIPYVRYL 
 3 CAA0021   100.0%  ---------------------------------VYQHQKAMKPWIQPKTKVIPYVRYL 
 4 CAA0019   100.0%  -------------------------------KTVYQHQKAMKPWIQPKTKVIPYVRYL 
 5 CAA0018   100.0%  ------------------------------LKTVYQHQKAMKPWIQPKTKVIPYVRYL 
 6 CAA0017   100.0%  -------------------------ALPQYLKTVYQHQKAMKPWIQPKTKVIPYVRYL 
 7 CAA0015   100.0%  ----------------------QKFALPQYLKTVYQHQKAMKPWIQPKTKVIPYVRYL 
 9 CAA0009   100.0%  --------KNRLNFLKKISQRYQKFALPQYLKTVYQHQK------------------- 

10 CAA0013   100.0%  --------------LKKISQRYQKFALPQY---------------------------- 

11 CAA0008   100.0%  --------KNRLNFLKKISQRYQ----------------------------------- 




15 CAA0012   100.0%  --------------------RYQKFALPQYLKTVYQHQK------------------- 

16 CAA0016   100.0%  ------------------------FALPQYLK-------------------------- 

Citation: 1

Synergistic effect between different milk-derived peptides and proteins

Cited Entries: LFB0085, LFB0092, CAA0021

Authors:Lopez-Exposito, I., Pellegrini, A., Amigo, L., Recio, I.
Journal: Journal of Dairy Science 2008, 91(6).
CrossRef External Link
Abstract: Antimicrobial peptides derived from food proteins constitute a new field in the combined use of antimicrobial agents in food. The best examples of milk-derived peptides are those constituted by bovine lactoferricin [lactoferrin f(1741)] (LFcin-B) and bovine αs2-casein f(183207). The aim of this work was to study if the antimicrobial activity of a natural compound employed in food preservation, nisin, could be enhanced by combination with the aforementioned milk-derived peptides. Furthermore, the possibility of a synergistic effect between these peptides and bovine lactoferrin (LF) against Escherichia coli and Staphylococcus epidermidis was also studied. Finally, the most active combinations were assayed against the foodborne pathogens Listeria monocytogenes and Salmonella choleraesuis. Results showed a synergistic effect when LFcin-B was combined with bovine LF against E. coli. In the same way, the combination of LFcin-B with bovine LF was synergistic against Staph. epidermidis. Bovine LF and nisin increased their antimicrobial activity when they were assayed together with bovine αs2-casein f(183-207). It is important to note the synergistic effect among LFcin-B and bovine LF, because both compounds might be simultaneously in the suckling gastrointestinal tract and could, therefore, have a protective effect on it. The other synergistic effect high-lighted is that between αs2-casein f(183207) and nisin against L. monocytogenes because of the ability of L. monocytogenes to develop resistance to nisin.
Keywords: synergism; milk-derived antibacterial peptide; antibacterial milk protein
Citation: 2

Identification of antibacterial peptides from ovine alphas2-casein

Cited Entries: LFB0085, CAA0020, CAA0021, CAA0023, CAA0024, CAA0025, CAA0026

Authors:Lopez-Exposito, I., Gomez-Ruiz, J.A., Amigo, L., Recio, I.
Journal: International Dairy Journal 2006, 16(9).
CrossRef External Link
Abstract: The aim of this work was to isolate and identify antibacterial peptides present in a pepsin digest of ovine αs2-casein. A protein digest with antibacterial properties was first separated by ion exchange chromatography. The fractions most active against Escherichia coli ATCC 25922 were fractionated by semi-preparative RP-HPLC, and the identification of the active peptides was carried out by on-line and off-line RP-HPLC-ESI-MS/MS. Following this strategy, 10 different peptides were identified, all corresponding to the C-terminal region of the ovine αs2-casein. Four of them were chemically synthesized and showed antibacterial activity against several Gram-positive and Gram-negative bacteria. Among the synthesized peptides, ovine αs2-casein f(165181) exhibited the highest antibacterial potency against all bacteria tested. The antimicrobial activity was compared with that of other previously described peptides like lactoferricin and fragment f(183207) of bovine αs2-casein.
Keywords: [alpha]s2-Casein; Antibacterial peptide; Electrospray mass spectrometry; Ovine milk
Citation: 3

Identification of the initial binding sites of alphas2-casein f(183-207) and effect on bacterial membranes and cell morphology

Cited Entries: LFB0085, LFB0092, CAA0021

Authors:Lopez-Exposito, I., Amigo, L., Recio, I.
Journal: Biochimica et Biophysica Acta (BBA) - Biomembranes 2008, 1778(10).
CrossRef External Link
Abstract: The aim of this work was to identify the initial binding sites to the bacterial membranes of the antimicrobial peptide αs2-casein f(183207) and also to acquire further insight into membrane permeabilization of this peptide. Furthermore, cell morphology was studied by transmission electron microscopy. In all the experiments, bovine LFcin was employed as a comparison. Results showed that initial binding sites of αs2-casein f(183207) peptide were lipoteichoic acid in Gram-positive bacteria and lipopolysaccharide in Gram-negative. The peptide was able to permeabilize the outer and inner membranes. Moreover, the αs2-casein peptide f(183207) generated pores in the outer membrane of Gram-negative bacteria and in the cell wall of Gram-positive bacteria. In the Gram-negative bacteria, f(183207) originated cytoplasm condensation, and in the Gram-positive bacteria the cytoplasmic content leaked into the extracellular medium. Furthermore, the experiments of inner and outer membrane permeabilization performed with LFcin-B showed that this peptide also has the ability to permeabilize both the inner and outer membranes.
Keywords: Antimicrobial peptides; Binding sites; Permeabilization; [alpha]s2-Casein; Milk-derived bioactive peptides

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