Urease: Difference between revisions
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Urease is an enzyme that converts [[urea]] into ammonia. | |||
==Uses== | ==Uses== | ||
Urease autocatalyzes the conversion of [[urea]] to [[ammonia]] | Urease autocatalyzes the conversion of [[urea]] to [[ammonia]] | ||
| Line 8: | Line 8: | ||
* Bacteria and fungi produce urease | * Bacteria and fungi produce urease | ||
* Urease is present in several types of plant seeds (watermelon, pea, and bean) | * Urease is present in several types of plant seeds (watermelon, pea, and bean) | ||
==Hazards== | |||
==Character== | |||
* For jack bean urease<ref>{{cite web|url=http://www.toyobousa.com/enzyme-URH-201.html|title=UREASE from Jack bean}}</ref> | |||
** Optimal temperature: 60 °C | |||
** Optimal pH 6.0 | |||
==Production== | ==Production== | ||
===Extraction=== | ===Extraction=== | ||
| Line 22: | Line 28: | ||
==Purification== | ==Purification== | ||
===Materials=== | ===Materials=== | ||
: '''Citric acid buffer''': Solution of | : '''Citric acid buffer''': Solution of '''sodium citrate''' with 4% w/w [[citric acid]] | ||
: '''Phosphate neutral buffer''': Solution of {{#Chem:KH2PO4}} with 150% w/w {{#Chem:Na2HPO4}} | : '''Phosphate neutral buffer''': Solution of {{#Chem:KH2PO4}} with 150% w/w {{#Chem:Na2HPO4}} | ||
===Process=== | ===Process=== | ||
Repeat: | |||
# Combine 5% v/v '''acid buffer''' with solution | |||
# Add propanone dropwise until it becomes ''slightly'' cloudy | |||
# Stand overnight | |||
# Centrifuge at 0° for 30 min | |||
# Filter, discard filtrate | |||
#: The residue is crystals of urease. | |||
# | # IF (the crystals are sufficiently homogeneous) THEN exit loop | ||
# Dissolve residue in '''neutral buffer''' solution | # Dissolve residue in '''neutral buffer''' solution | ||
# Centrifuge | # Centrifuge | ||
# Retain clear fluid | # Retain clear fluid | ||
==See Also== | ==See Also== | ||
* [[urea]] | * [[urea]] | ||
* [[urine]] | * [[urine]] | ||
* [[ammonia]] | * [[ammonia]] | ||
[[Category:Complex Organics]] | * {{cite pub | ||
|first1=G.|last1=Gorin | |||
|first2=C.C.last2=Chin | |||
|publication=Biochim.Biophys.Acta. | |||
|title=Urease. V. Some observations on the procedure for its isolation. | |||
|url=https://pubmed.ncbi.nlm.nih.gov/5849826/ | |||
|courtesy=US NIH | |||
|volume=99 | |||
|pages=418 | |||
|year=1965}} | |||
* {{cite pub | |||
|first1=H.G.|last1=Schlegel | |||
|first2=H.|last2=Kaltwasser | |||
|publlication=Methods of Enzymatic Analysis | |||
|title=Urease | |||
|volume=2 | |||
|pages=1081 | |||
|year=1962}} | |||
*{{cite pub | |||
|first1=J.B.|last1=Sumner | |||
|first2=D.B.|last2=Hand | |||
|publication=J.Am.Chem.Soc. | |||
|title=THE ISOELECTRIC POINT OF CRYSTALLINE UREASE | |||
|volume=31 | |||
|pages-=1255 | |||
|year=1929}} | |||
==References== | |||
<references/> | |||
[[Category:Complex Organics]][[Category:NOWA]] | |||
Latest revision as of 22:19, 25 November 2024
Urease is an enzyme that converts urea into ammonia.
Uses
Urease autocatalyzes the conversion of urea to ammonia
- CO(NH2)2 + H2O{urease2 NH3 + CO2}→
- Optimal catalytic activity occurs at approximately 30°C and pH of 7.4-8.0.
- In a perfectly pure sample, 1g of urease will produce 100g of ammonia nitrogen from urea in 5 minutes at 20°C.
Natural occurrence
- Bacteria and fungi produce urease
- Urease is present in several types of plant seeds (watermelon, pea, and bean)
Hazards
Character
- For jack bean urease[1]
- Optimal temperature: 60 °C
- Optimal pH 6.0
Production
Extraction
Since urease is soluble in propanone, a solvent with a very high vapor pressure, most extractions salve biomass containing urease in propanone, filter and evaporate. The entire process is carried out at low temperatures, often 2-4°C
The source is typically freshly germinated seeds: pea seeds, dehusked watermelon seeds, or jack bean meal.
Catalytic solution
- Combine 160cc of dry propanone with 340cc of distilled water
- Mix in 100g of seed pulp
- Filter, discard residue
- Dry until all scent of propanone is gone
- (If necessary) add water to dissolve any precipitate
- The solution may be added to sources of urea to convert them to ammonia
Purification
Materials
- Citric acid buffer: Solution of sodium citrate with 4% w/w citric acid
- Phosphate neutral buffer: Solution of KH2PO4 with 150% w/w Na2HPO4
Process
Repeat:
- Combine 5% v/v acid buffer with solution
- Add propanone dropwise until it becomes slightly cloudy
- Stand overnight
- Centrifuge at 0° for 30 min
- Filter, discard filtrate
- The residue is crystals of urease.
- IF (the crystals are sufficiently homogeneous) THEN exit loop
- Dissolve residue in neutral buffer solution
- Centrifuge
- Retain clear fluid
See Also
- urea
- urine
- ammonia
- Gorin, G. (1965) "Urease. V. Some observations on the procedure for its isolation."
Biochim.Biophys.Acta. 99; pp418.
link courtesy US NIH. - Schlegel, H.G.; Kaltwasser, H. (1962) "Urease".; pp1081.
- Sumner, J.B.; Hand, D.B. (1929) "THE ISOELECTRIC POINT OF CRYSTALLINE UREASE".
J.Am.Chem.Soc. 31