|-
| align="center" colspan="2" |
|-
| colspan="2" bgcolor="#dddddd" | Identifiers
|-
| bgcolor="#e7dcc3" | Symbol(s)
| bgcolor="#eeeeee" | [AMY2A] AMY2
|-
| bgcolor="#e7dcc3" | Entrez
| bgcolor="#eeeeee" | [279]
|- class="hiddenStructure"
| bgcolor="#e7dcc3" | OMIM
| bgcolor="#eeeeee" | [104650]
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| bgcolor="#e7dcc3" | RefSeq
| bgcolor="#eeeeee" | [NM_000699]
|-
| bgcolor="#e7dcc3" | UniProt
| bgcolor="#eeeeee" | [P04746]
|- class="hiddenStructure"
| bgcolor="#e7dcc3" | PDB
| bgcolor="#eeeeee" | []
|-
| colspan="2" bgcolor="#dddddd" | Other data
|- class="hiddenStructure"
| bgcolor="#e7dcc3" | EC number
| bgcolor="#eeeeee" | [3.2.1.1]
|-
| bgcolor="#e7dcc3" | Locus
| bgcolor="#eeeeee" | Chr. 1[p21.1]
|-
|}
Amylase (EC [3.2.1.1]) (CAS# 9014-71-5) is a digestiveenzyme classified as a saccharidase (an enzyme that cleaves polysaccharides). It is a constituent of human pancreatic juice and saliva, where it acts to breakdown long-chain carbohydrates (such as starch) into maltose which is then subsequently degraded by maltase, an enzyme, to glucose.
Amylase is also synthesized by many plants during the ripening of fruit and during the germination of cereal grains. Grain amylase is key to the production of malt. Many microbes also produce amylase to degrade extracellular starches.
There are two isoforms of human amylase: pancreatic and salivary amylase. They behave differently on isoelectric focusing, and can also be separated in testing by using specific monoclonal antibodies.
Ptyalin
Ptyalin is the name given to the amylase found in saliva that breaks starch down into maltose and dextrin.
Substances acts upon ptyalin
Ptyalin act on starch breaking it down to soluble starch.(amylodextrin,erythrodextrin,achrodextrin and finally maltose).
Ptyalin acts on alpha 1,4 glucosidic linkages,compound hydrolysis requires an enzyme which acts on branched products.
Optimum conditions for ptyalin
Optimum pH-5.6 - 6.9
Room temperatue- 37 degrees Celsius
Presence of certain anions and activators:
Chlorine and Bromine - most effective
Iodine - less effective
Sulfate and Phosphate - least effective
The Ptyalin Debate
For almost 200 years, medical science has understood that young infant saliva has very low levels of the amylase enzyme ptyalin. This has fuelled an on-going debate by numerous doctors including Chavasse, Sonsino, Tilden, Routh, Husley, Youmans, Dalton, Page, Shelton and Fry; to eliminate farinaceous (starchy) foods from the diet of infants, until full dentition [growing of teeth] which then co-incides with an infant's increased levels of ptyalin. Fray, Kathy: "Oh Baby...Birth, Babies & Motherhood Uncensored", page 410-411. Random House NZ, 2005. ISBN1-86941-713-5
Beta-amylase also catalyzes the hydrolysis of a-1,4 glycosidic bonds but only from the non-reducing end to yield maltose molecules. Beta-amylase is present in germinating seeds prior to germination whereas a-amylase and proteases appear once germination has begun.
The test for amylase is easy to perform and has been the main test for pancreatitis. Labs will usually measure either pancreatic amylase, or total amylase. If only pancreatic amylase is measured, an increase will not be noted with mumps or other salivary gland trauma.
Unfortunately, because of the small amount present, timing is critical when sampling blood for this measurement. Blood should preferably be taken soon after a bout of pancreatitis pain, otherwise it is excreted rapidly by the kidneys.
Total amylase readings of over 10X the upper limit of normal (ULN) are suggestive of pancreatitis. 5-10x times the ULN may indicate ileus or duodenal disease or renal failure, and lower elevations are commonly found in salivary gland disease.
