β-LG f(92-101) [id=BLA0006]

Producer Organism : Native Protein : Production Method :
Cow β-lactoglobulin synthetic
Activity : Antibacterial
Target Organisms :

Gram-positive: Active against Bacillus subtilis BGA, Micrococcus luteus ATCC 4698, Staphylococcus epidermidis ATCC 12228, Staphylococcus lentus, Streptococcus zooepidemicus.

Gram-negative: Active against Escherichia coli ATCC 25922, Bordetella bronchiseptica.

NOTE: No activity against Klebsiella pneumoniae ATCC 13883, Serratia marcescens ATCC 8100, Staphylococcus aureus ATCC 25923, Salmonella typhimurium, Candida albicans ATCC 2091 .

Description :
Production method: synthetic.

Seventh residue replaced with arginine
Length : 10 Mass (Da): 1 234.58 Common Amino Acids : VKL
Isolectric Point : 10.25 Net Charge : 2 Absent Amino Acids : ACEFGHIMNPQSW
Basic Residues : 3 Acidic Residues : 1 Hydrophobic Residues : 4
Polar Residues : 2 Boman Index : -19.53 Hydropathy Index : -0.18
Aliphatic Index : 136 Instability Index : 0 Extinction Coefficient : 1490
Absorbance 280nm : 165.56

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.

Citation: 1

Isolation and characterization of four bactericidal domains in the bovine beta-lactoglobulin

Cited Entries: BLA0002, BLA0003, BLA0004, BLA0005, BLA0006

Authors:Pellegrini, A., Dettling, C., Thomas, U., Hunziker, P.
Journal: Biochimica et Biophysica Acta (BBA) - General Subjects 2001, 1526(2).
CrossRef External Link
Abstract: Proteolytic digestion of bovine β-lactoglobulin by trypsin yielded four peptide fragments with bactericidal activity. The peptides were isolated and their sequences were found as follows: VAGTWY (residues 1520), AASDISLLDAQSAPLR (residues 2540), IPAVFK (residues 7883) and VLVLDTDYK (residues 92100). The four peptides were synthesized and found to exert bactericidal effects against the Gram-positive bacteria only. In order to understand the structural requirements for antibacterial activity, the amino acid sequence of the peptide VLVLDTDYK was modified. The replacement of the Asp (98) residue by Arg and the addition of a Lys residue at the C-terminus yielded the peptide VLVLDTRYKK which enlarged the bactericidal activity spectrum to the Gram-negative bacteria Escherichia coli and Bordetella bronchiseptica and significantly reduced the antibacterial capacity of the peptide toward Bacillus subtilis. By data base searches with the sequence VLVLDTRYKK a high homology was found with the peptide VLVATLRYKK (residues 5564) of human blue-sensitive opsin, the protein of the blue pigment responsible for color vision. A peptide with this sequence was synthesized and assayed for bactericidal activity. VLVATLRYKK was strongly active against all the bacterial strains tested. Our results suggest a possible antimicrobial function of β-lactoglobulin after its partial digestion by endopeptidases of the pancreas and show moreover that small targeted modifications in the sequence of β-lactoglobulin could be useful to increase its antimicrobial function.
Keywords: [beta]-Lactoglobulin; Antibacterial activity; antimicrobial; Antibiotics; Bactericidal peptide

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