αs2-casein f(198-222) or f(183-207) [id=CAA0020]

Synonym: Cp2

Producer Organism : Native Protein : Production Method :
Cow αs2-casein Enzymatic hydrolysis and Purification with LC method
Activity : Antibacterial
Target Organisms :

Gram-positive: Active against Listeria innocua CECT 910 T, Staphylococcus epidermidis CECT 231, Staphylococcus carnosus CECT 4491T, Enterococcus faecalis CECT 795 at 0.5 mM, Listeria innocua FSAW 2305 (MIC=125 痢/ml), Listeria innocua (MIC=16 然), Listeria monocytogenes FSAW 2310 (MIC=125 痢/ml), Listeria monocytogenes NCTC 11994 (MIC=125 痢/ml), Micrococcus flavus DSM 1790 (MIC=16 然), Bacillus cereus P7 (MIC=16 然), Bacillus subtilis FSAW 0320 (MIC=125 痢/ml), Streptococcus thermophilus Rs (MIC=8 然).

Gram-negative: Active against Serratia marcescens CECT 854 at 0.5 mM, Escherichia coli ATCC 25922 (MIC=16 然), Escherichia coli MC 1061 (MIC=16 然), Escherichia coli NCTC 8196 (MIC=250 痢/ml), Citrobacter freundii FSAW 0801 (MIC=500 痢/ml), Salmonella enteritidis FSAW 3420 (MIC=250 痢/ml), Salmonella typhimurium FSAW 3412 (MIC=125 痢/ml).

NOTE: No activity against Enterobacter aerogenes NCTC 10006 (>1000 痢/ml) .

Description :
Production method: Pepsin hydrolysis and purification with LC method.

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

Identification of two distinct antibacterial domains within the sequence of bovine alphas2-casein

Cited Entries: CAA0013, CAA0019, CAA0020

Authors:Recio, I., Visser, S.
Journal: Biochimica et Biophysica Acta (BBA) - General Subjects 1999, 1428(2-3).
CrossRef External Link
Abstract: Two distinct domains with antibacterial activity were isolated from a peptic hydrolysate of bovine αs2-casein. The digested αs2-casein was fractionated by cation-exchange chromatography, after which the peptides in the two active fractions obtained were separated by high-performance liquid chromatography and sequenced by electrospray-ionization tandem mass spectrometry. The major component in each active fraction, f(183207) and f(164179), was further purified and the antibacterial activity of these components was tested against several microorganisms. Depending on the target bacterial strain, these peptides exhibited minimum inhibitory concentrations between 8 and 99 μM. Peptide f(183207) exhibited a consistently higher antibacterial activity than f(164179), although both peptides showed a comparable hemolytic effect. A method of in situ enzymatic hydrolysis on a cation-exchange membrane to obtain a fraction enriched in the most active antibacterial domain is presented. The antibacterial and hemolytic activities are discussed in relation to the structure and hydrophobicity of the peptides.
Keywords: Antibacterial peptide; [alpha]s2-Casein; Electrospray mass spectrometry; Hydrolysis of membrane-bound 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

Two ion-exchange chromatographic methods for the isolation of antibacterial peptides from lactoferrin: In situ enzymatic hydrolysis on an ion-exchange membrane

Cited Entries: LFB0006, LFB0010, LFB0085, LFB0092, LFB0147, LFB0148, LFB0151, CAA0013, CAA0019, CAA0020

Authors:Recio, I., Visser, S.
Journal: Journal of Chromatography A 1999, 831(2).
CrossRef External Link
Abstract: Two ion-exchange chromatographic methods are reported for the rapid isolation of antibacterial peptides from lactoferrin (LF). Using the first method, a pepsin hydrolysate of LF was fractionated by bead-based cation-exchange chromatography. After removal of weakly bound material by washing with ammonia, highly purified lactoferricin-B (LFcin-B) was obtained in a single step by elution with 2 M NaCl. Some other cationic peptides, copurified as minor components, were also characterised by N-terminal sequencing, mass spectrometry and antibacterial activity determination. With the second method, cheese whey was filtered through a cation-exchange membrane, and the selectively bound LF was directly hydrolysed in situ with pepsin. Inactive LF fragments were washed off the membrane with ammonia, and a fraction enriched in LFcin-B was obtained by further elution with 2 M NaCl. The membrane method is more rapid and offers several economic advantages.
Keywords: peptides; ANTIBACTERIAL agents; Lactoferrin
Citation: 4

Isolation and characterisation of a novel antibacterial peptide from bovine alphaS1-casein

Cited Entries: CAA0005, CAA0020, CAA0039, CAA0040, CAA0041

Authors:McCann, K.B., Shiell, B.J., Michalski, W.P., Lee, A., Wan, J., Roginski, H., Coventry, M.J.
Journal: International Dairy Journal 2006, 16(4).
CrossRef External Link
Abstract: Bovine casein was hydrolysed with a range of proteolytic enzymes including pepsin, trypsin, α-chymotrypsin and β-chymotrypsin, and assessed for antibacterial activity. The pepsin digest of bovine casein, which showed antibacterial activity, was fractionated using reverse phase high performance liquid chromatography and the antibacterial peptides isolated were characterised using electrospray ionisation mass spectrometry. Two antibacterial peptides were identified, a novel peptide (Cp1) which corresponded to residues 99109 of bovine αS1-casein and a previously reported peptide (Cp2) which corresponded to residues 183207 of bovine αS2-casein. The minimum inhibitory concentration (MIC) of Cp1 and Cp2 were determined against a range of bacterial cultures. Cp1 exhibited an MIC of 125 μg mL−1 against all Gram-positive bacteria tested, and MIC ranging between 125 and >1000 μg mL−1 against the Gram-negative bacteria tested. Cp2 was generally far more potent against the Gram-positive bacteria, exhibiting an MIC of 21 μg mL−1, compared to MICs ranging from 332 to >664 μg mL−1 against most of the Gram-negative bacteria tested.
Keywords: Antibacterial peptides; Bovine casein
Citation: 5

Identification of antibacterial peptides from bovine kappa-casein

Cited Entries: CAA0016, CAA0020, CAK0006, CAK0008, CAK0009, CAK0010, CAK0011, CAK0014, CAK0017, CAK0018, CAK0019, CAB0003, CAB0004, CAB0005

Authors:Lopez-Exposito, I., Minervini, F., Amigo, L., Recio, I.
Journal: Journal of Food Protection 2006, 69(12).
Abstract: The objective of the present study was to identify antimicrobial peptides present in several digests of commercial caseins with gastric enzymes. The most active hydrolysate against Escherichia coli ATCC 25922 and Listeria innocua CECT 910T corresponded to a pepsin digest of bovine kappa-casein. The protein digest was first separated by semipreparative high-performance liquid chromatography (HPLC), and the most active fractions were again subjected to a second chromatographic step. Finally, identification of the active peptides was carried out by online and offline HPLC-electrospray ionization-tandem mass spectrometry. By means of this technique, 21 peptides were identified in the active HPLC fractions. Although most were derived from bovine kappa-casein, some of the identified fragments corresponded to beta-casein and alpha(s)-casein fragments, a result of the presence of small amounts of these proteins in the preparation of kappa-casein. Some of the peptides identified were chemically synthesized and showed antibacterial effects against several gram-positive and gram-negative bacteria. Among the synthesized peptides, kappa-casein f(18-24), f(30-32), and f(139-146) were most effective against all bacteria tested. The antibacterial effect of these peptides is discussed in relation to their amino acid sequences.

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