Polyglutamic acid

Polyglutamic acid (PGA) is a polymer of the amino acid glutamic acid (GA). Depending on where the individual monomers connect, PGA can be gamma PGA (poly-γ-glutamic acid, γ-PGA), the form where the peptide bonds are between the amino group of GA and the carboxyl group at the end of the GA side chain, or alpha PGA, the form where the alpha-carboxyl is used to form the peptide bond.

Polyglutamic acid

Gamma PGA
Names
Systematic IUPAC name
Poly[imino[1-carboxy-4-oxo-1,4-butanediyl]]
Identifiers
ChemSpider
  • none
Properties
(C5H7NO3)n
Molar mass variable
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Gamma PGA is formed by bacterial fermentation. It is a major constituent of the Japanese food nattō and has a wide range of uses.

Alpha PGA has been investigated as a drug delivery system.

Structure

Both form of PGA are linked together by peptide bonds. Because the glutamic acid has a chiral center, both forms of PGA can be made from L-glutamic acid, D-glutamic acid, or a mixture of both. In practical use, alpha PGA is almost universally purely contain the L form,[1] while gamma PGA tends to have a mixture of both.[2]

Properties

Gamma PGA is non-immunogenic and biodegradable.[2] It hydrolyzes in hot water.[3]

Both forms are amphiphilic, water-soluble, and have a negative charge.[1][2]

Synthesis

Gamma PGA is industrially made by fermentation. The biosynthetic process starts with racemerization by RacE, which converts L-glutamate to D-glutamate. A set of genes on an operon then proceed to assemble the molecule and move it out of the bacterial cell.[2]

Alpha PGA is industrially made by chemical synthesis, using a ring-opening polymerization reaction.[1]

Occurrence

Gamma PGA is made by a number of Bacillus species. The best-known source is natto, where it is produced by Bacillus subtilis.[4] It is also an important component of the Bacillus anthracis capsule, hiding the bacterium from the immune system and allowing it to grow unchecked.[5]

Uses

Gamma PGA has been used for food, medicine,[6][7] cosmeceuticals[8] and water treatment.[9]

Alpha PGA is used as a delivery aid for paclitaxel, an anticancer drug,[10] under the generic name of paclitaxel poliglumex.[11] Research is underway for its application in a treatment of type I diabetes and its potential use in the production of an AIDS vaccine.

Water treatment

The "PolyGlu PGα21Ca" water flocculant, based on a mixture of gamma PGA, calcium sulfate, and calcium carbonate,[12] is used by the International Organization for Migration to treat water for refugees.[13]

G-PGA covalently incorporated into microfiltration membranes via attachment to their membrane pore surfaces exhibited super-high heavy metal sorption ability.[14] G-PGA was found to bind and efficiently remove 99.8% of lead ions from water via a suitable low-pressure ultrafiltration technique.[15]

References
  1. Zhang, Y; Song, W; Lu, Y; Xu, Y; Wang, C; Yu, DG; Kim, I (25 April 2022). "Recent Advances in Poly(α-L-glutamic acid)-Based Nanomaterials for Drug Delivery". Biomolecules. 12 (5): 636. doi:10.3390/biom12050636. PMC 9138577. PMID 35625562.
  2. Li, D; Hou, L; Gao, Y; Tian, Z; Fan, B; Wang, F; Li, S (2 March 2022). "Recent Advances in Microbial Synthesis of Poly-γ-Glutamic Acid: A Review". Foods (Basel, Switzerland). 11 (5). doi:10.3390/foods11050739. PMC 8909396. PMID 35267372.
  3. Goto, A.; Kunioka, M. (1992). "Biosynthesis and Hydrolysis of Poly(γ-glutamic acid) from Bacillus subtilis IF03335". Bioscience, Biotechnology, and Biochemistry. 56 (7): 1031–1035. doi:10.1271/bbb.56.1031. PMID 27286372.
  4. Johnson, Leah C.; Akinmola, Adekunle Titus; Scholz, Carmen (March 2022). "Poly(glutamic acid): From natto to drug delivery systems". Biocatalysis and Agricultural Biotechnology. 40: 102292. doi:10.1016/j.bcab.2022.102292. S2CID 246628249.
  5. Jang, J; Cho, M; Chun, JH; Cho, MH; Park, J; Oh, HB; Yoo, CK; Rhie, GE (September 2011). "The poly-γ-D-glutamic acid capsule of Bacillus anthracis enhances lethal toxin activity". Infection and Immunity. 79 (9): 3846–54. doi:10.1128/IAI.01145-10. PMC 3165481. PMID 21690241.
  6. Choi, Jae-Chul; Uyama, Hiroshi; Sung, Chul-Hoon Lee and Moon-Hee (2015-06-28). "Promotion Effects of Ultra-High Molecular Weight Poly-γ-Glutamic Acid on Wound Healing". Journal of Microbiology and Biotechnology. 25 (6): 941–945. doi:10.4014/jmb.1412.12083. PMID 25791849.
  7. Lee, Na-Ri; Go, Tae-Hun; Lee, Sang-Mee; Jeong, Seong-Yun; Park, Geun-Tae; Hong, Chang-Oh; Son, Hong-Joo (2014-04-21). "In vitro evaluation of new functional properties of poly-γ-glutamic acid produced by Bacillus subtilis D7". Saudi Journal of Biological Sciences. 21 (2): 153–158. doi:10.1016/j.sjbs.2013.09.004. ISSN 1319-562X. PMC 3942858. PMID 24600308.
  8. Eroglu, I. (March 12, 2022). "Polyglutamic Acid in Skincare, Explained". Ejollify. Retrieved April 12, 2022.
  9. Bringing Safe Drinking Water to the World
  10. C. Li; D.F. Yu; A. Newman; F. Cabral; C. Stephens; N.R. Hunter; L. Milas; S. Wallace (1998). "Complete regression of well-established tumors using a novel water-soluble poly(L-glutamic acid)-paclitaxel conjugate" (PDF). Cancer Research. 58 (11): 2404–2409. PMID 9622081.
  11. Singer, JW (5 December 2005). "Paclitaxel poliglumex (XYOTAX, CT-2103): a macromolecular taxane". Journal of Controlled Release. 109 (1–3): 120–6. doi:10.1016/j.jconrel.2005.09.033. PMID 16297482.
  12. Yanagibashi, Tomokazu; Kobayashi, Motoyoshi; Omori, Keisuke (22 August 2019). "Application of Poly-γ-Glutamic Acid Flocculant to Flocculation–Sedimentation Treatment of Ultrafine Cement Suspension". Water. 11 (9): 1748. doi:10.3390/w11091748. A food-derived amino acid-based polymer, namely the PGAF (PGα21Ca, Japan Poly-Glu Co., Ltd., Osaka, Japan), was used as the flocculant. Figure 3 shows the appearance of PGα21Ca. PGα21Ca is a natural polymer consisting of γ-PGA, which is an amino acid obtained from Bacillus subtilis [7]. PGα21Ca is composed of cross-linked γ-PGA with an average molecular weight of 107 and natural minerals such as calcium sulfate and calcium carbonate hydrate.
  13. "UN Migration Agency, Japan Hand Over New Water Purification Facility in Sierra Leone". International Organization for Migration.
  14. Bhattacharyya, D (April 1998). "Novel poly-glutamic acid functionalized microfiltration membranes for sorption of heavy metals at high capacity". Journal of Membrane Science. 141 (1): 121–135. doi:10.1016/S0376-7388(97)00301-3.
  15. Inbaraj et al. (2006)
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.