Pectinase

Last updated
Endopolygalacturonase I
Identifiers
Organism Aspergillus niger
SymbolpgaI
UniProt P26213
Other data
EC number 3.2.1.15
Search for
Structures Swiss-model
Domains InterPro

Pectinases are a group of enzymes that breaks down pectin, a polysaccharide found in plant cell walls, through hydrolysis, transelimination and deesterification reactions. [1] [2] Commonly referred to as pectic enzymes, they include pectolyase, pectozyme, and polygalacturonase, one of the most studied and widely used[ citation needed ] commercial pectinases. It is useful because pectin is the jelly-like matrix which helps cement plant cells together and in which other cell wall components, such as cellulose fibrils, are embedded. Therefore, pectinase enzymes are commonly used in processes involving the degradation of plant materials, such as speeding up the extraction of fruit juice from fruit, including apples and sapota. Pectinases have also been used in wine production since the 1960s. [3] The function of pectinase in brewing is twofold, first it helps break down the plant (typically fruit) material and so helps the extraction of flavors from the mash. Secondly the presence of pectin in finished wine causes a haze or slight cloudiness. Pectinase is used to break this down and so clear the wine.

Contents

Pectinases can be extracted from fungi such as Aspergillus niger . The fungus produces these enzymes to break down the middle lamella in plants so that it can extract nutrients from the plant tissues and insert fungal hyphae. If pectinase is boiled it is denatured (unfolded) making it harder to connect with the pectin at the active site, and produce as much juice.

Pectinase in nature

Pectinase enzymes used today are naturally produced by fungi and yeasts (50%), insects, bacteria and microbes (35%) and various plants (15%), [4] but cannot be synthesized by animal or human cells. [5] In plants, pectinase enzymes hydrolyze pectin that is found in the cell wall, allowing for new growth and changes to be made. Similarly to their role in plants, pectinases break down pectin during the developmental stage of fungi.

Characterizations

Pectinase enzymes are classified based on how their enzymatic reaction proceeds with various pectic substances (through transelimination or hydrolysis), the preferred substrate (pectin, pectic acid or oligo-n-galacturonate) and if the cleavage that occurs is random or end-wise. [5] [6]

Reaction pathway

Pectinases depolymerize pectin through hydrolysis, trans-elimination and deesterification reaction processes, breaking down the ester bond that holds together the carboxyl and methyl groups in pectin. [5]

Endo-polygalacturonase progresses through a reaction along the following pathway: [7]

1,4-alpha-D-galacturonosyl)n+m + H2O = (1,4-alpha-D-galacturonosyl)n + (1,4-alpha-D-galacturonosyl)m

Crystal structures

All pectinase enzyme structures include a prism-shaped right-handed cylinder made up of seven to nine parallel β-helices. The three parallel β-helices that create the prism shape of the structure are referred to as PB1, PB2 and PB3, with PB1 and PB2 creating an antiparallel β and PB3 sitting perpendicularly to PB2. All substrate binding sites of the various esterases, hydrolases, and lyases are located on an outer cleft of the central parallel β-helix structure between protruding loops on the structure and PB1. [8]

Optimum environment

As with all enzymes, pectinases have an optimum temperature and pH at which they are most active. For example, a commercial pectinase might typically be activated at 45 to 55 °C and work well at a pH of 3.0 to 6.5. [9]

Industrial uses

Pectinase enzymes play various roles in both the fruit juice and wine industries. They are used for clarification in fruit juices and also speed up fruit juice extraction through enzymatic liquefaction of fruit pulp. In addition, pectinase enzymes aid in formation of pulpy products in the fruit juice industry. Pectinase enzymes are used for extracting juice from purée. This is done when the enzyme pectinase breaks down the substrate pectin and the juice is extracted. The enzyme pectinase lowers the activation energy needed for the juice to be produced and catalyzes the reaction.

Pectinases are useful in the wine industry by extracting anthocyanin from the fruit, effectively intensifying the wine coloring. [10] Pectinase can also be used to extract juices from cell walls of plants cells.

Pectinases are also used for retting in the textile industry. [11] Addition of chelating agents or pretreatment of the plant material with acid enhance the effect of the enzyme.

Related Research Articles

<span class="mw-page-title-main">Cell wall</span> Outermost layer of some cells

A cell wall is a structural layer surrounding some types of cells, just outside the cell membrane. It can be tough, flexible, and sometimes rigid. It provides the cell with both structural support and protection, and also acts as a filtering mechanism. Cell walls are absent in many eukaryotes, including animals, but are present in some other ones like fungi, algae and plants, and in most prokaryotes. A major function is to act as pressure vessels, preventing over-expansion of the cell when water enters.

<span class="mw-page-title-main">Orange juice</span> Juice made from oranges

Orange juice is a liquid extract of the orange tree fruit, produced by squeezing or reaming oranges. It comes in several different varieties, including blood orange, navel oranges, valencia orange, clementine, and tangerine. As well as variations in oranges used, some varieties include differing amounts of juice vesicles, known as "pulp" in American English, and "(juicy) bits" in British English. These vesicles contain the juice of the orange and can be left in or removed during the manufacturing process. How juicy these vesicles are depend upon many factors, such as species, variety, and season. In American English, the beverage name is often abbreviated as "OJ".

β-Galactosidase Family of glycoside hydrolase enzymes

β-Galactosidase, is a glycoside hydrolase enzyme that catalyzes hydrolysis of terminal non-reducing β-D-galactose residues in β-D-galactosides.

<span class="mw-page-title-main">Pectin</span> Structural carbohydrate in the cell walls of land plants and some algae

Pectin is a heteropolysaccharide, a structural acid contained in the primary lamella, in the middle lamella, and in the cell walls of terrestrial plants. The principal, chemical component of pectin is galacturonic acid which was isolated and described by Henri Braconnot in 1825. Commercially produced pectin is a white-to-light-brown powder, produced from citrus fruits for use as an edible gelling agent, especially in jams and jellies, dessert fillings, medications, and sweets; and as a food stabiliser in fruit juices and milk drinks, and as a source of dietary fiber.

<span class="mw-page-title-main">Exoenzyme</span> Exoenzyme

An exoenzyme, or extracellular enzyme, is an enzyme that is secreted by a cell and functions outside that cell. Exoenzymes are produced by both prokaryotic and eukaryotic cells and have been shown to be a crucial component of many biological processes. Most often these enzymes are involved in the breakdown of larger macromolecules. The breakdown of these larger macromolecules is critical for allowing their constituents to pass through the cell membrane and enter into the cell. For humans and other complex organisms, this process is best characterized by the digestive system which breaks down solid food via exoenzymes. The small molecules, generated by the exoenzyme activity, enter into cells and are utilized for various cellular functions. Bacteria and fungi also produce exoenzymes to digest nutrients in their environment, and these organisms can be used to conduct laboratory assays to identify the presence and function of such exoenzymes. Some pathogenic species also use exoenzymes as virulence factors to assist in the spread of these disease-causing microorganisms. In addition to the integral roles in biological systems, different classes of microbial exoenzymes have been used by humans since pre-historic times for such diverse purposes as food production, biofuels, textile production and in the paper industry. Another important role that microbial exoenzymes serve is in the natural ecology and bioremediation of terrestrial and marine environments.

<span class="mw-page-title-main">Pectic acid</span> Chemical compound

Pectic acid, also known as polygalacturonic acid, is a water-insoluble, transparent gelatinous acid existing in over-ripe fruit and some vegetables. It is a product of pectin degradation in plants, and is produced via the interaction between pectinase and pectin In the early stage of development of fruits, the pectic substance is a water-insoluble protopectin which is converted into pectin by the enzyme protopectinase during ripening of fruit. In over-ripe fruits, due to the presence of pectic methyl esterase enzyme, the pectin gets largely converted to pectic acid which is water-insoluble. Due to this reason both immature and over-ripe fruits are not suitable for making jelly and only ripe fruits are used.

Saprobionts are organisms that digest their food externally and then absorb the products. This process is called saprotrophic nutrition. Fungi are examples of saprobiontic organisms, which are a type of decomposer.

Endo-1,4-β-xylanase is any of a class of enzymes that degrade the linear polysaccharide xylan into xylose, thus breaking down hemicellulose, one of the major components of plant cell walls:

<i>Siraitia grosvenorii</i> Sweet plant fruit extract

Siraitia grosvenorii, also known as monk fruit, monkfruit or luohan guo, is a herbaceous perennial vine of the gourd family, Cucurbitaceae. It is native to southern China. The plant is cultivated for its fruit extract, called mogrosides, which creates a sweetness sensation 250 times stronger than sucrose. Mogroside extract has been used as a low-calorie sweetener for drinks and in traditional Chinese medicine.

β-Glucosidase Class of enzymes

β-Glucosidase is an enzyme that catalyses the following reaction:

<span class="mw-page-title-main">Pectinesterase</span> Class of enzymes

Pectinesterase (EC 3.1.1.11; systematic name pectin pectylhydrolase) is a ubiquitous cell-wall-associated enzyme that presents several isoforms that facilitate plant cell wall modification and subsequent breakdown. It catalyzes the following reaction:

Pectate lyase is an enzyme involved in the maceration and soft rotting of plant tissue. Pectate lyase is responsible for the eliminative cleavage of pectate, yielding oligosaccharides with 4-deoxy-α-D-mann-4-enuronosyl groups at their non-reducing ends. The protein is maximally expressed late in pollen development. It has been suggested that the pollen expression of pectate lyase genes might relate to a requirement for pectin degradation during pollen tube growth.

Pectin lyase, also known as pectolyase, is a naturally occurring pectinase, a type of enzyme that degrades pectin. It is produced commercially for the food industry from fungi and used to destroy residual fruit starch, known as pectin, in wine and cider. In plant cell culture, it is used in combination with the enzyme cellulase to generate protoplasts by degrading the plant cell walls.

The enzyme tannase (EC 3.1.1.20) catalyzes the following reaction:

<span class="mw-page-title-main">Polygalacturonase</span>

Endo-polygalacturonase (EC 3.2.1.15, pectin depolymerase, pectolase, pectin hydrolase, and poly-α-1,4-galacturonide glycanohydrolase; systematic name (1→4)-α-D-galacturonan glycanohydrolase (endo-cleaving)) is an enzyme that hydrolyzes the α-1,4 glycosidic bonds between galacturonic acid residues:

Polygalacturonase inhibitor proteins (PGIPs), also known as polygalacturonase-inhibiting proteins, are plant proteins capable of inhibiting the action of polygalacturonase (PG) enzymes produced by bacterial and fungal pathogens. PGs can be produced by pathogens to degrade the polygalacturonan component of plant cell walls. PGIPs are leucine-rich repeat glycoproteins of approximately 360 amino acids in length, and PGIPs may reduce the activity of PGs by one or two orders of magnitude. Both competitive and non-competitive inhibition has been observed for various PGIPs. However, no inhibition of endogenous plant PGs that participate in fruit ripening by PGIPs have been reported.

<span class="mw-page-title-main">Glucanase</span>

Glucanases are enzymes that break down large polysaccharides via hydrolysis. The product of the hydrolysis reaction is called a glucan, a linear polysaccharide made of up to 1200 glucose monomers, held together with glycosidic bonds. Glucans are abundant in the endosperm cell walls of cereals such as barley, rye, sorghum, rice, and wheat. Glucanases are also referred to as lichenases, hydrolases, glycosidases, glycosyl hydrolases, and/or laminarinases. Many types of glucanases share similar amino acid sequences but vastly different substrates. Of the known endo-glucanases, 1,3-1,4-β-glucanase is considered the most active.

Inulinase is an enzyme with systematic name 1-β-D-fructan fructanohydrolase. It catalyses the reaction

<span class="mw-page-title-main">Fungal extracellular enzyme activity</span> Enzymes produced by fungi and secreted outside their cells

Extracellular enzymes or exoenzymes are synthesized inside the cell and then secreted outside the cell, where their function is to break down complex macromolecules into smaller units to be taken up by the cell for growth and assimilation. These enzymes degrade complex organic matter such as cellulose and hemicellulose into simple sugars that enzyme-producing organisms use as a source of carbon, energy, and nutrients. Grouped as hydrolases, lyases, oxidoreductases and transferases, these extracellular enzymes control soil enzyme activity through efficient degradation of biopolymers.

<i>Rhizopus oryzae</i> Species of fungus

Rhizopus oryzae is a filamentous heterothallic microfungus that occurs as a saprotroph in soil, dung, and rotting vegetation. This species is very similar to Rhizopus stolonifer, but it can be distinguished by its smaller sporangia and air-dispersed sporangiospores. It differs from R. oligosporus and R. microsporus by its larger columellae and sporangiospores. The many strains of R. oryzae produce a wide range of enzymes such as carbohydrate digesting enzymes and polymers along with a number of organic acids, ethanol and esters giving it useful properties within the food industries, bio-diesel production, and pharmaceutical industries. It is also an opportunistic pathogen of humans causing mucormycosis.

References

  1. ↑ Sakai T, Sakamoto T, Hallaert J, Vandamme EJ (1993). "Pectin, pectinase and protopectinase: production, properties, and applications". Advances in Applied Microbiology. 39: 213–94. doi:10.1016/s0065-2164(08)70597-5. PMID   8213306.
  2. ↑ Singh, Ram Sarup; Singh, Taranjeet; Pandey, Ashok (2019-01-01), Singh, Ram Sarup; Singhania, Reeta Rani; Pandey, Ashok; Larroche, Christian (eds.), "Chapter 1 - Microbial Enzymes—An Overview", Advances in Enzyme Technology, Biomass, Biofuels, Biochemicals, Elsevier, pp. 1–40, ISBN   978-0-444-64114-4 , retrieved 2021-10-20
  3. ↑ "Pectinase". Enzyme India. Archived from the original on 26 March 2010. Retrieved 26 March 2010.
  4. ↑ Melton, Laurence (2019). Encyclopedia of Food Chemistry (Volume 2 ed.). Elsevier. p. 271.
  5. 1 2 3 Saranaj, P; Naidu, M.A. (2014). "Microbial Pectinases: A Review". ResearchGate.
  6. ↑ Sakai T, Sakamoto T, Hallaert J, Vandamme EJ (1993). "Pectin, pectinase and protopectinase: production, properties, and applications". Advances in Applied Microbiology. 39: 213–94. doi:10.1016/s0065-2164(08)70597-5. PMID   8213306.
  7. ↑ "BRENDA - Information on EC 3.2.1.15 - endo-polygalacturonase". brenda-enzymes.org. Retrieved 2021-10-20.
  8. ↑ Gummadi, Sathyanarayana N.; Manoj, N.; Kumar, D. Sunil (2007), Polaina, Julio; MacCabe, Andrew P. (eds.), "Structural and Biochemical Properties of Pectinases", Industrial Enzymes: Structure, Function and Applications, Dordrecht: Springer Netherlands, pp. 99–115, doi:10.1007/1-4020-5377-0_7, ISBN   978-1-4020-5377-1 , retrieved 2021-10-20
  9. ↑ "Pectinase". Enzyme India. Archived from the original on 26 March 2010. Retrieved 26 March 2010.
  10. ↑ Saranaj, P; Naidu, M.A. (2014). "Microbial Pectinases: A Review". ResearchGate.
  11. ↑ Rebello, Sharrel; Anju, Mohandas; Aneesh, Embalil Mathachan; Sindhu, Raveendran; Binod, Parameswaran; Pandey, Ashok (13 July 2017). "Recent advancement sin the production and application of microbial pectinases: an overview" (PDF). Reviews in Environmental Science and Bio/Technology. 16 (3): 381–394. doi:10.1007/s11157-017-9437-y. S2CID   90607593.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.