Characterization of an l-α,β-diaminopropionic acid polymer with comb-like structure isolated from a poly(ε-l-lysine)-producing Streptomyces sp
Polymers of basic amino acids function as polycationic compounds under physiological conditions and exhibit intriguing biological properties, such as antimicrobial and antiviral activities, immunopotentiating ability, and DNA-binding activity. Poly(ε- l -lysine) (ε-PL) produced by some strains of St...
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Published in | Applied microbiology and biotechnology Vol. 105; no. 8; pp. 3145 - 3157 |
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Main Authors | , , , , , , |
Format | Journal Article |
Language | English |
Published |
Berlin/Heidelberg
Springer Berlin Heidelberg
01.04.2021
Springer Nature B.V |
Subjects | |
Online Access | Get full text |
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Summary: | Polymers of basic amino acids function as polycationic compounds under physiological conditions and exhibit intriguing biological properties, such as antimicrobial and antiviral activities, immunopotentiating ability, and DNA-binding activity. Poly(ε-
l
-lysine) (ε-PL) produced by some strains of
Streptomyces
spp. is a cationic homopolymer of
l
-lysine linking between ε-amino and α-carboxylic acid functional groups and has been used as a food preservative based on its biocompatibility and biodegradability. An ε-PL-producing strain of
Streptomyces
sp. USE-33 was found to secrete a novel polycationic substance into its culture broth along with ε-PL. High-performance liquid chromatography analyses and one- and two-dimensional
1
H and
13
C nuclear magnetic resonance (NMR) experiments, accompanied by NMR titration studies, revealed that the secreted substance was poly[β-(
l
-diaminopropionyl-
l
-diaminopropionic acid)], PAP, characterized by an isopeptide backbone linking between the β-amino and α-carboxylic acid groups of
l
-α,β-diaminopropionic acid (
l
-Dpr) with pendent
l
-Dpr residues. PAP had a molecular weight of 500 to 1400, and copolymers composed of the two amino acids
l
-Dpr and
l
-lysine were not detected in the producer strain USE-33. The strain coproduced high levels of the two poly(amino acid)s in the presence of glycerol, citrate, and ammonium sulfate at pH 4.0 in a two-stage cultivation procedure. PAP exhibited strong inhibitory activities against several yeasts and weaker activities against bacteria than ε-PL. PAP may share a number of biological functions with ε-PL, and the use of PAP along with ε-PL has potential as a specific and advanced material for technical applications in various fields.
Key points
•
Novel cationic poly(amino acid) was found in an ε-PL-producing Streptomyces species.
•
The
l
-α,β-diaminopropionic acid polymer was characterized by a comb-like structure.
•
The novel poly(amino acid), PAP, exhibited antibacterial and antifungal activities.
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0175-7598 1432-0614 |
DOI: | 10.1007/s00253-021-11257-3 |