TY - JOUR
T1 - Isolation and biochemical characterization of a novel lantibiotic mutacin from Streptococcus mutans
AU - Novak, J.
AU - Caufield, P. W.
AU - Miller, E. J.
PY - 1994
Y1 - 1994
N2 - Certain members of the indigenous biota of humans produce antimicrobial substances called bacteriocins, which inhibit other bacteria, including members of their own species. One of these substances, mutacin, is made by Streptococcus mutans, a member of the oral biota. Mutacin inhibits other mutans streptococci as well as many gram-positive exogenous pathogens. Here, we report for the first time the purification and partial biochemical characterization of a lanthionine-containing mutacin peptide from S. mutans T8. The biologically active peptide was isolated from the broth cultures by ultrafiltration and differential precipitation. The final mutacin preparation was homogeneous as shown by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and N-terminal amino acid sequencing. A molecular mass of the peptide was estimated by electrospray ionization mass spectroscopy to be 3,244.64 ± 1.15 Da. Its amino acid composition indicates the presence of lanthionine and likely β-methyllanthionine in a total of about 25 amino acids. Because α,β-unsaturated amino acids, the precursors of lanthionine residues, are often found in lantibiotics, we carried out the addition reaction of the mutacin with N-(methyl)mercaptoacetamide. The subsequent electrospray ionization mass spectroscopy analysis indicated the presence of two reaction products with M(r)s of 3,350.45 and 3,456.0. These are interpreted as the mutacin molecule with the addition of one and two molecules of reagent to the unsaturated amino acids, respectively. Sequencing of the peptide revealed an N-terminal amino acid sequence of Asn-Arg-Trp- Trp-Gln-Gly-Val-Val.
AB - Certain members of the indigenous biota of humans produce antimicrobial substances called bacteriocins, which inhibit other bacteria, including members of their own species. One of these substances, mutacin, is made by Streptococcus mutans, a member of the oral biota. Mutacin inhibits other mutans streptococci as well as many gram-positive exogenous pathogens. Here, we report for the first time the purification and partial biochemical characterization of a lanthionine-containing mutacin peptide from S. mutans T8. The biologically active peptide was isolated from the broth cultures by ultrafiltration and differential precipitation. The final mutacin preparation was homogeneous as shown by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and N-terminal amino acid sequencing. A molecular mass of the peptide was estimated by electrospray ionization mass spectroscopy to be 3,244.64 ± 1.15 Da. Its amino acid composition indicates the presence of lanthionine and likely β-methyllanthionine in a total of about 25 amino acids. Because α,β-unsaturated amino acids, the precursors of lanthionine residues, are often found in lantibiotics, we carried out the addition reaction of the mutacin with N-(methyl)mercaptoacetamide. The subsequent electrospray ionization mass spectroscopy analysis indicated the presence of two reaction products with M(r)s of 3,350.45 and 3,456.0. These are interpreted as the mutacin molecule with the addition of one and two molecules of reagent to the unsaturated amino acids, respectively. Sequencing of the peptide revealed an N-terminal amino acid sequence of Asn-Arg-Trp- Trp-Gln-Gly-Val-Val.
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U2 - 10.1128/jb.176.14.4316-4320.1994
DO - 10.1128/jb.176.14.4316-4320.1994
M3 - Article
C2 - 8021218
AN - SCOPUS:0028306988
SN - 0021-9193
VL - 176
SP - 4316
EP - 4320
JO - Journal of bacteriology
JF - Journal of bacteriology
IS - 14
ER -