Action of a cell wall proteinase from Lactococcus lactis subsp. cremoris SK11 on bovine ? s1-casein

Abstract

The cell wall-associated proteinase from Lactococcus lactis subsp. cremoris SK11 was partially purified and incubated with alpha s1-casein for various times up to 48 h. Sixteen trifluoroacetic acid-soluble oligopeptide hydrolysis products were identified by determination of the amino acid sequence. Eleven of these oligopeptides originated from the 78-residue sequence comprising the C-terminal region of alpha s1-casein and were present among the products after the first 60 min of digestion. Three oligopeptides from the N-terminal region and two others from the central region of the alpha s1-casein sequence were also present among the early digestion products although in smaller amounts than most of the oligopeptides from the C-terminal region. No clear consensus sequence of amino acid residues surrounding the cleavage sites could be identified.

The oligopeptides of sweet and acid cheese whey

“…several Lactococcus strains already identified in previous studies . This may indicate that the CEPs active in the cheese milk degrade asl-casein with a pattern similar to that described for CEP from Lactococcus lactis ssp cremoris SKII (Reid et al, 1991). However, this latter produced, in addition to peptides from the N-terminal (1-17,17-23, and 34-37) and central region of asl-casein, II components from the Cterminal region which were not detected in the Quarg-like cheese whey.…”

“…This difference was attributed by Visser et al (1994) to the mixed-type specificity of the enzyme used by Monnet et al (1992). The case of the commercial starter culture growth in cheese milk where a variety of enzymes acts sirnultaneously on the four casein fractions is more complicated th an that studied by Visser et al (1994), Monnet et al (1992), andReid et al (1991) whose studies considered only model systems with a single casein fraction and an active CEP preparation obtained from a single strain. This might explain the high number of cleavage positions of x-casein found in the whey in our study, in comparison with the fewer positions observed in the model systems.…”

“…- (Juillard et al, 1995), and us1-casein (Reid et al, 1991) has recently been investigated. Lactococcus proteinases showed sorne chymosin-Iike effects when acting on x-casein and more than 100 different oligopeptides were produced from the~-casein hydrolysis.…”

Hydrophilic and hydrophobic peptides produced in cheese by wild Lactococcus lactis strains

“…Numerous studies in aqueous buffers have identified that different lactocepins (cell-envelope associated proteinase of L. lactis) produce different peptides from casein hydrolysis (Monnet et al 1986(Monnet et al , 1989Visser et al 1988Visser et al , 1994Reid et al 1991aReid et al , b, 1994Juillard et al 1995). During casein degradation in vitro with cell-wall proteinase fractions, less bitterness was generated by L. lactis AM1, a strain with lactocepin III, than by L. lactis HP, a strain with lactocepin I (Visser et al 1983a).…”

Estudio De La Transferencia De Masa en El Salado en Seco De Queso De Cabra Y Sus Implicaciones Durante La Maduración

“…Sin embargo se aislaron péptidos de κ-CN en queso Feta y su formación podría ser el resultado de la acción de una proteinasa lactococcal en el enlace Met95-Ala96, que exhibe las características necesarias de un sitio de escisión para una enzima como esa (Reid et al, 1991;Michaelidou et al, 1998). …”