E-Poly-L-lysine

Yamanaka, K., Maruyama, C., Takagi, H., and Hamano, Y. (2008) e-Poly-L-lysine dispersity is controlled by a highly unusual nonribosomal peptide synthetase. Nat. Chem. Biol., 4, 766-772. 

Figure 4.1 Structure of (a) a-poly(L-lysine) and (b) E-poly(L-lysine).

The main applications of proteins are in the nutraceutical and pharmaceutical industries. The specific antimicrobial properties of e-poly-L-lysine promoted its utilization in the food industry in Japan, whereas poly-a,p-aspartic acid is mainly used as a polydispersant in detergents. ... 

An area that is of important practical benefit lies in how biointerfaces consisting of chemically derivatized biocompatible polymers are applied to biosensing applications. These include biotin functionalized copolymer (i.e., poly(L-lysine)-graft-poly(ethylene glycol)-biotin) or polymers bearing histidine-binding nitrilotriacetate (NTA)-metal ion complexes.Importantly, these polymers impart both... 

Trypsin preferentially catalyzed the condensation of trimethylsilanol under mild conditions (87% HMDS). Subs tial condensation of trimethylsilanol was not observed in the negative control, non-specific protein (i.e. BSA, y-globulins), small molecule (i.e. CaCl2, imidazole, N-methylimidazole), and polypeptide (i.e. poly-L-lysine) reactions in comparison to the raw material (< 1% HMDS). Based on an inqjurity study with small molecule inhibitors (23), the exceptional activity of trypsin and a-chymotrypsin observed in the original enzyme-catalyzed condensation study was soley due to a tryptic impurity. The tertiary... 

Genome shuffling enhanced E-poly-L-lysine production by improving glucose tolerance of streptomyces graminearus. Appl. Biochem. Biotechnol, 166, 414-423. 

Other important polyamides include Cyanophycin from Cyanobacteria and -poly-L-lysine from Streptomyces albulus. The former is a repeating heteropolymer comprised of dipeptide units of aspartate and arginine, whereas the latter is a homopolymer with lysine as the main component. Cyanophycin is used as a water softener and dispersant, whereas e-poly-L-lysine is used as a food [133] preservative as well as an adsorbent [131]. 

Kito M, Takimoto R, Yoshida T, Nagasawa T (2002a), Purification and characterization of an e-poly-L-lysine-degrading enzyme from an e-poly-L-lysine-producing strain of Streptomyces albulus . Arch Microbiol, 178, 325-330. 

Kito M, Onjii Y, Yoshida T, Nagasawa T (2002b), Occurrence of e-poly-L-lysine-degrading enzyme in e-poly-L-lysine-tolerant sphingobacterium multivorum OJIO purification and characterization , FEMS Microbiol Lett, 207, 147-151. 

Yoshida T, Nagasawa T (2003), e-Poly-L-lysine microbial production, biodegradation and appUcation potential , Appl Microbiol Biotechnol, 62, 21-26. 

POLY(AMINO acids). Both anionic [e.g., poly(L-aspartic acid) and poly(glutamic acid)] and cationic [e.g., poly[L-lysine)] poly(amino acids) have been suggested as potential drug carriers. Poly(L-lysine) is a homopolymer cosisting of repeating units of L-lysine. It exhibits some affinity for cancer cells and possesses antimicrobial and antiviral properties. It also shows... 

Fig. 53. Mannosylated dendron based on a poly-L-lysine scaffold. This construct leads to subnanomolar inhibitory potency against uropathogenic E. coli,336...

Gegg, C.V., and Ktzlcr, M.E. (1993) Directional coupling of synthetic peptides to poly-L-lysine and applications to the ELISA. Anal. Biochem. 210, 309-313. 

In proteins in particular the peptide bonds contribute to the CD-spectra of the macromolecule. Here, CD-spectra reflect the secondary structure of proteins, which are derived from CD-spectra of model macromolecules with only one defined secondary structure (like poly-L-lysine at given pH values) or based on spectra of proteins with known structures (e.g.,from X-ray crystallography). The amount of a-helices or -sheets in the unknown structure is calculated by linear combination of the reference spectra [150,151]. 

The reaction of the p-nitrophenyl esters with the polymer (4) was studied in dimethyl sulfoxide ( DMSO ) solution in the presence of triethylamine at 25°C. The poly-L-lysine derivatives obtained have different IR absorption spectra from those of the starting compounds, and have absorptions assigned to the nucleic acid bases. Poly( e,N-Ade-L-lysine )(5) was soluble in DMSO and ethylene glycol, and also in water below pH 3, where it was present as a protonated form. In dimethylformamide (... 

DMF ) solution, the poly-L-lysine containing 53 mol % adenine units was soluble, while the polymer containing 74 mol % adenine units was insoluble. Poly( e,N-Thy-L-lysine )(d) and poly( e, N-Ura-L-lysine )(7) was soluble in DMSO, DMF and 6 N-hydrochloric acid. 

The spectral data of these polymers are tabulated in Table 1 and 2. From these data, it was concluded that the activated ester of Ade-PNP (2) reacted only with e-amino group of poly-L-lysine, and did not react with amino group of the adenine base. Figure 1, 2 and 3 show their NMR spectra. 

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