Poly-a,p-aspartic acid

Nishiyama N, Yokoyama M, Aoyagi T, Okano T, Sakurai Y, Kataoka K. Preparation and characterization of self-assembled polymer-metal complex micelle from cis-dichloro-diammineplatinum (II) and polyfethylene glycol)-poly(a, p- aspartic acid) block copolymer in an aqueous medium. Langmuir 1999 15 377—383. 

Proteins are composed of amino acids linked by peptide bonds. Two main biosynthetic pathways for protein production have been identified so far the ribosomal and the non-ribosomal-multi-enzyme paths. The proteins are mainly heteropolymers composed by a variety of amino acids however, three poly(amino acid)s can be obtained through the multi-enzyme pathway cyanophycin (aspartic acid-arginine dipeptide), s-poly-L-lysine and poly-a,p-aspartic acid (Figure 1.5). 

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. ... 

Additionally, compounds such as a-arginyl aspartic acid dipeptide, modified cyanophycin containing less arginine, and poly-a,P-DL-aspartic acid were used as primers by the respective CphA [76],... 

Poly-a,p-DL-aspartic acid, sodium salt. See Sodium polyaspartate Polyavin PEN. See polyethylene Polyazelaic polyanhydride Synonyms PAPA Formula H[OCO(CH2)7CO]nOH Uses Epoxy resin flexibilizer specialty PU polyol... 

The two structures starting from L-aspartic acid are shown in Scheme 10. Pathway A is the acid-catalyzed thermal condensation, and B is the noncatalyzed thermal condensation. The polysuccinimide intermediates hydrolyze at the points indicated to give mixtures of a, p poly (d,l- aspartic acid) salts. Regardless of the stereochemistry of the starting aspartic acid, d or l, the final polymeric product is always the dl racemate. 

OF and Lipase P were also shown to aggregate with block copolymers made of poly[(A-acetylimino)ethylene] and poly[(A-pentanoylimino)ethylene], with about 30% increased activity for the ester hydrolysis and 200% increased activity for the ester synthesis in aqueous solutions compared to the native enzymes. The activity of egg white lysozyme located in the core of PEG—poly(o ,j8-aspartic acid) micelles was investigated by colorimetric methods and revealed an increase for p-nitrophenyl-penta-A-acetyl-/ -chitopentaoside as substrate. By the determination of kinetic constants of enzymatic reaction, it was demonstrated that the increase in the enzymatic activity was... 

References to polypeptides bearing long alkyl sidechains are almost confined to the esters of poly(a,L-glutamic acid) (PyAG-n) and poly (a or p,L-asparfic acid) (PpAA-n or PaAA-n) whose chemical stmctures are depicted in Fig. 1. In these compounds the alkyl sidechain is connected to the mainchain by a carboxylate group that is directly anchored to the backbone in the case of poly(P-peptide)s and through a methylene or ethylene spacer in poly (a-aspartate)s and poly(a-... 

Poly-a,P-DL-aspartic acid, sodium salt. See Sodium polyaspartate Polybutadiene dimethacrylate... 

Poly((a,P)-D,L-aspartic acid), sodium salt 94525-0 1-6 DL-Aspartic acid, homopolymer, R sodium salt (C4H7N04)4- jrNa... 

The substrate membrane was then derivatized by the permeation of a 5% solution (v/v) of silane 3-glycidoxypropyltrimethoxysilane (GOPS) in o-xylene, toluene, or hexane through the membrane under convective flow at 25°C-60°C for 2 h. Polyamino acid (poly-L-aspartic acid [PLAA] and poly-[a,p]-DL-aspartic acid [PDAA], Mw 6-36 kD) was then reacted to the expoxy end group with 100 mL of a 100 mg/L aqueous solution at pH 92-9.5. The reaction scheme is given as follows ... 

Another synthetic polymer that has shown promise in recent clinical trials for the micellar encapsulation of anticancer dmgs is a block copolymer of PEG and poly (aspartic acid) [PEG-Z -P(Asp)]. Doxombicin can be covalently attached to PEG-fi-P(Asp) through the free carboxylic acid groups on aspartic acid, and the block copolymer then forms micelles in solution with the hydrophobic aspartic acid and dmg block forming the core (Yokoyama et al. 1991 Kataoka et al. 1993). As typically occurs, the hydrated PEG chains significantly increased blood circulation... 

The B block may consist of a water-soluble polymer, for example, poly(aspartic acid) P(Asp), that is rendered hydrophobic by the chemical conjugation of a hydrophobic drug (Yokoyama et al., 1992, 1993, 1996 Nakanishi et al., 2001), or is formed through the association of two oppositely changed polyions (polyion complex micelles) (Hatada etal., 1995,1998 Kataoka etal., 1996). Drugs used to couple the B block include cyclophosphamide, doxorubicin, cisplatin, pyrene, and iodine derivative of benzoic acid (Kwon and Kataoka, 1995 Trubetskoy et al., 1997 Yu etal., 1998). 

---