β-LG f(15-20) [id=BLA0002]

Synonym: LGTD2

Producer Organism : Native Protein : Production Method :
Cow β-lactoglobulin Enzymatic hydrolysis and Purification with LC method/Synthetic
Activity : Antibacterial
Target Organisms :

Gram-positive: Active against Staphylococcus aureus ATCC 25923, Staphylococcus epidermidis ATCC 12228, Staphylococcus lentus, Bacillus subtilis BGA, Micrococcus luteus ATCC 4698.

NOTE: No activity against Streptococcus zooepidemicus, Salmonella typhimurium, Escherichia coli ATCC 25922, Klebsiella pneumoniae ATCC 13883, Serratia marcescens ATCC 8100, Bordetella bronchiseptica, Candida albicans ATCC 2091 .

Description :
Production method: Trypsin hydrolysis and purification with LC method/Synthetic.

Length : 6 Mass (Da): 695.80 Common Amino Acids : TAVGWY
Isolectric Point : 6.09 Net Charge : Absent Amino Acids : CDEFHIKLMNPQRS
Basic Residues : 0 Acidic Residues : 0 Hydrophobic Residues : 3
Polar Residues : 3 Boman Index : 6.41 Hydropathy Index : 0.45
Aliphatic Index : 65 Instability Index : 0 Extinction Coefficient : 6990
Absorbance 280nm : 1398

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 15–20), AASDISLLDAQSAPLR (residues 25–40), IPAVFK (residues 78–83) and VLVLDTDYK (residues 92–100). 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 55–64) 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
Citation: 2

Food-protein enzymatic hydrolysates possess both antimicrobial and immunostimulatory activities: a ‘cause and effect’ theory of bifunctionality

Cited Entries: ALA0002, CAS0001, BLA0002

Authors:Biziulevič, ius, G. A., Kislukhina, O. V., Kazlauskaitė, , J., Žukaitė, , V.
Journal: FEMS Immunology & Medical Microbiology 2006, 46(1): 131-138.
CrossRef External Link
Abstract: The antimicrobial activity (the ability to activate the microbial autolytic system) and immunostimulatory activity (the ability to improve the phagocytic cell functioning) of 20 food-protein hydrolysates [five food proteins (casein, α-lactalbumin, β-lactoglobulin, ovalbumin and serum albumin) hydrolyzed with four gastrointestinal proteinases (trypsin, α-chymotrypsin, pepsin and pancreatin)] were examined. All the food-protein hydrolysates acted antimicrobially in vitro towards all 24 microbial strains tested: autolysis of 20 naturally autolyzing strains was activated, with the autolysis activation index (KA) ranging from 1.04 to 22.0, while autolysis was induced to values of 2.81–56.7% in four naturally nonautolyzing strains. When given to mice per os, all the food-protein hydrolysates enhanced the phagocytosing capacity of peritoneal macrophages, with the enhancement index (KI) ranging from 1.02 to 1.41. A direct correlation between KA and KI was observed. We make the presumption that KI is a function of KA.
Keywords: food-protein hydrolysates, antimicrobial activity, immunostimulatory activity, microbial autolytic system, macrophage, phagocytosing capacity, a ‘cause and effect’ theory of bifunctionality

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