Human Salivary Amylase - Revision history

Sam Himstedt: User:Sam Himstedt/sandbox 1 moved to Human Salivary Amylase

Sam Himstedt — Fri, 29 Apr 2022 21:08:03 GMT

User:Sam Himstedt/sandbox 1 moved to Human Salivary Amylase

←Older revision

Revision as of 21:08, 29 April 2022

Sam Himstedt at 21:07, 29 April 2022

Sam Himstedt — Fri, 29 Apr 2022 21:07:04 GMT

←Older revision		Revision as of 21:07, 29 April 2022
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	== Active Site ==		== Active Site ==
-	The active site forms a large, deep cleft where larger starches bind and are hydrolyzed into smaller ones. This active site is at the <scene name='91/910719/Act2/2'>aspartate residue at position 197</scene> and the <scene name='91/910719/Act1/1'>glutamate residue at position 233</scene>. This active site plays a role in the enzyme’s function as a processive enzyme. This means that salivary amylase does not immediately detach from its substrates and can carry out several rounds of hydrolysis before detaching. The mechanism for hydrolyzing starches involves a proton donor group, <scene name='91/910719/Act1/1'>Glu 233</scene> cleaving the glycosidic bond. Then, a nucleophile, <scene name='91/910719/Act2/2'>Asp 197</scene>, forms a covalent intermediate between the enzyme and substrate. This intermediate is then attacked by a hydroxyl ion, formed by <scene name='91/910719/Act1/1'>Glu 233</scene>, resulting in an unaltered enzyme and the products of hydrolysis.	+	The <scene name='91/910719/Act/1'>active site</scene> forms a large, deep cleft where larger starches bind and are hydrolyzed into smaller ones. This <scene name='91/910719/Act/1'>active site</scene> is at the <scene name='91/910719/Act2/2'>aspartate residue at position 197</scene> and the <scene name='91/910719/Act1/1'>glutamate residue at position 233</scene>. This active site plays a role in the enzyme’s function as a processive enzyme. This means that salivary amylase does not immediately detach from its substrates and can carry out several rounds of hydrolysis before detaching. The mechanism for hydrolyzing starches involves a proton donor group, <scene name='91/910719/Act1/1'>Glu 233</scene> cleaving the glycosidic bond. Then, a nucleophile, <scene name='91/910719/Act2/2'>Asp 197</scene>, forms a covalent intermediate between the enzyme and substrate. This intermediate is then attacked by a hydroxyl ion, formed by <scene name='91/910719/Act1/1'>Glu 233</scene>, resulting in an unaltered enzyme and the products of hydrolysis.

	== Ligands ==		== Ligands ==

Sam Himstedt at 20:45, 29 April 2022

Sam Himstedt — Fri, 29 Apr 2022 20:45:57 GMT

←Older revision		Revision as of 20:45, 29 April 2022
Line 7:		Line 7:

	== Structure ==		== Structure ==
-	Human salivary amylase is a protein consisting of a single chain made up of three domains, <scene name='91/910719/A/1'>A</scene>, <scene name='91/910719/B/1'>B</scene>, and <scene name='91/910719/C/1'>C</scene>. The overall structure of this protein is barrel shaped, much like the three individual domains of the protein. This multi domain structure is stabilized by several disulfide bridges. These disulfide bridges are seen between the cysteine residues at positions <scene name='91/910719/Di1/14'>28 and 86</scene>, <scene name='91/910719/Di2/3'>70 and 115</scene>, <scene name='91/910719/Di3/3'>141 and 160</scene>, <scene name='91/910719/Di4/2'>378 and 384</scene>, and positions <scene name='91/910719/Di5/2'>450 and 462</scene>.	+	Human salivary amylase is a protein consisting of a single chain made up of three domains, <scene name='91/910719/A/1'>A</scene>, <scene name='91/910719/B/1'>B</scene>, and <scene name='91/910719/C/1'>C</scene>. The overall structure of this protein is barrel shaped, much like the three individual domains of the protein. This <scene name='91/910719/Multi/1'>multi domain</scene> structure is stabilized by several disulfide bridges. These disulfide bridges are seen between the cysteine residues at positions <scene name='91/910719/Di1/14'>28 and 86</scene>, <scene name='91/910719/Di2/3'>70 and 115</scene>, <scene name='91/910719/Di3/3'>141 and 160</scene>, <scene name='91/910719/Di4/2'>378 and 384</scene>, and positions <scene name='91/910719/Di5/2'>450 and 462</scene>.

	== Active Site ==		== Active Site ==

Sam Himstedt at 20:42, 29 April 2022

Sam Himstedt — Fri, 29 Apr 2022 20:42:19 GMT

←Older revision		Revision as of 20:42, 29 April 2022
Line 7:		Line 7:

	== Structure ==		== Structure ==
-	Human salivary amylase is a protein consisting of a single chain made up of three domains, A, <scene name='91/910719/B/1'>B</scene>, and <scene name='91/910719/C/1'>C</scene>. The overall structure of this protein is barrel shaped, much like the three individual domains of the protein. This multi domain structure is stabilized by several disulfide bridges. These disulfide bridges are seen between the cysteine residues at positions <scene name='91/910719/Di1/14'>28 and 86</scene>, <scene name='91/910719/Di2/3'>70 and 115</scene>, <scene name='91/910719/Di3/3'>141 and 160</scene>, <scene name='91/910719/Di4/2'>378 and 384</scene>, and positions <scene name='91/910719/Di5/2'>450 and 462</scene>.	+	Human salivary amylase is a protein consisting of a single chain made up of three domains, <scene name='91/910719/A/1'>A</scene>, <scene name='91/910719/B/1'>B</scene>, and <scene name='91/910719/C/1'>C</scene>. The overall structure of this protein is barrel shaped, much like the three individual domains of the protein. This multi domain structure is stabilized by several disulfide bridges. These disulfide bridges are seen between the cysteine residues at positions <scene name='91/910719/Di1/14'>28 and 86</scene>, <scene name='91/910719/Di2/3'>70 and 115</scene>, <scene name='91/910719/Di3/3'>141 and 160</scene>, <scene name='91/910719/Di4/2'>378 and 384</scene>, and positions <scene name='91/910719/Di5/2'>450 and 462</scene>.

	== Active Site ==		== Active Site ==

Sam Himstedt at 20:40, 29 April 2022

Sam Himstedt — Fri, 29 Apr 2022 20:40:44 GMT

←Older revision		Revision as of 20:40, 29 April 2022
Line 7:		Line 7:

	== Structure ==		== Structure ==
-	Human salivary amylase is a protein consisting of a single chain made up of three domains, A, B, and <scene name='91/910719/C/1'>C</scene>. The overall structure of this protein is barrel shaped, much like the three individual domains of the protein. This multi domain structure is stabilized by several disulfide bridges. These disulfide bridges are seen between the cysteine residues at positions <scene name='91/910719/Di1/14'>28 and 86</scene>, <scene name='91/910719/Di2/3'>70 and 115</scene>, <scene name='91/910719/Di3/3'>141 and 160</scene>, <scene name='91/910719/Di4/2'>378 and 384</scene>, and positions <scene name='91/910719/Di5/2'>450 and 462</scene>.	+	Human salivary amylase is a protein consisting of a single chain made up of three domains, A, <scene name='91/910719/B/1'>B</scene>, and <scene name='91/910719/C/1'>C</scene>. The overall structure of this protein is barrel shaped, much like the three individual domains of the protein. This multi domain structure is stabilized by several disulfide bridges. These disulfide bridges are seen between the cysteine residues at positions <scene name='91/910719/Di1/14'>28 and 86</scene>, <scene name='91/910719/Di2/3'>70 and 115</scene>, <scene name='91/910719/Di3/3'>141 and 160</scene>, <scene name='91/910719/Di4/2'>378 and 384</scene>, and positions <scene name='91/910719/Di5/2'>450 and 462</scene>.

	== Active Site ==		== Active Site ==

Sam Himstedt at 20:31, 29 April 2022

Sam Himstedt — Fri, 29 Apr 2022 20:31:56 GMT

←Older revision		Revision as of 20:31, 29 April 2022
Line 7:		Line 7:

	== Structure ==		== Structure ==
-	Human salivary amylase is a protein consisting of a single chain made up of three domains, A, B, and C. The overall structure of this protein is barrel shaped, much like the three individual domains of the protein. This multi domain structure is stabilized by several disulfide bridges. These disulfide bridges are seen between the cysteine residues at positions <scene name='91/910719/Di1/14'>28 and 86</scene>, <scene name='91/910719/Di2/3'>70 and 115</scene>, <scene name='91/910719/Di3/3'>141 and 160</scene>, <scene name='91/910719/Di4/2'>378 and 384</scene>, and positions <scene name='91/910719/Di5/2'>450 and 462</scene>.	+	Human salivary amylase is a protein consisting of a single chain made up of three domains, A, B, and <scene name='91/910719/C/1'>C</scene>. The overall structure of this protein is barrel shaped, much like the three individual domains of the protein. This multi domain structure is stabilized by several disulfide bridges. These disulfide bridges are seen between the cysteine residues at positions <scene name='91/910719/Di1/14'>28 and 86</scene>, <scene name='91/910719/Di2/3'>70 and 115</scene>, <scene name='91/910719/Di3/3'>141 and 160</scene>, <scene name='91/910719/Di4/2'>378 and 384</scene>, and positions <scene name='91/910719/Di5/2'>450 and 462</scene>.

	== Active Site ==		== Active Site ==
Line 13:		Line 13:

	== Ligands ==		== Ligands ==
-	Human salivary amylase has two ligands, calcium and chlorine. There are three metal binding sites ~~per domain~~ that bind calcium <ref name="pdb">DOI:10.2210/pdb1SMD/pdb</ref>. Studies that have investigated the function of these calcium ions have suggested that the presence of these ions greatly influences the thermostability of the enzyme <ref name="cal">DOI:10.2174/0929866526666190116162958</ref>. This may be a result of the fact that the enzyme moves from the cooler oral cavity to warmer regions of the gastrointestinal tract; however, the lower pH of these regions may inactivate salivary amylase. These metal binding sites occur at the <scene name='91/910719/Cal1/2'>asparagine residue at position 100</scene>, the <scene name='91/910719/Cal2/2'>arginine residue at position 158</scene>, the <scene name='91/910719/Cal3/2'>glutamate residue at position 167</scene>, and the <scene name='91/910719/Cal4/1'>histidine residue at position 201</scene>. Aside from calcium, chloride ions can bind to salivary amylase and there are three binding sites for this ligand <ref name="pdb"/>. These chloride binding sites are found at the <scene name='91/910719/Cl1/1'>arginine residue at position 195</scene>, the <scene name='91/910719/Cl2/1'>asparagine residue at position 298</scene>, and the <scene name='91/910719/Cl3/1'>arginine residue at position 337</scene>. It is suggested that the negative charge associated with these chloride ions is essential for the maximal catalytic activity of the enzyme <ref name="chl">DOI:10.1110/ps.0202602</ref>. Other ions, such as nitrate, can bind to these chloride binding sites, however, their ability to allosterically activate salivary amylase is much weaker.	+	Human salivary amylase has two ligands, calcium and chlorine. There are three metal binding sites that bind calcium <ref name="pdb">DOI:10.2210/pdb1SMD/pdb</ref>. Studies that have investigated the function of these calcium ions have suggested that the presence of these ions greatly influences the thermostability of the enzyme <ref name="cal">DOI:10.2174/0929866526666190116162958</ref>. This may be a result of the fact that the enzyme moves from the cooler oral cavity to warmer regions of the gastrointestinal tract; however, the lower pH of these regions may inactivate salivary amylase. These metal binding sites occur at the <scene name='91/910719/Cal1/2'>asparagine residue at position 100</scene>, the <scene name='91/910719/Cal2/2'>arginine residue at position 158</scene>, the <scene name='91/910719/Cal3/2'>glutamate residue at position 167</scene>, and the <scene name='91/910719/Cal4/1'>histidine residue at position 201</scene>. Aside from calcium, chloride ions can bind to salivary amylase and there are three binding sites for this ligand <ref name="pdb"/>. These chloride binding sites are found at the <scene name='91/910719/Cl1/1'>arginine residue at position 195</scene>, the <scene name='91/910719/Cl2/1'>asparagine residue at position 298</scene>, and the <scene name='91/910719/Cl3/1'>arginine residue at position 337</scene>. It is suggested that the negative charge associated with these chloride ions is essential for the maximal catalytic activity of the enzyme <ref name="chl">DOI:10.1110/ps.0202602</ref>. Other ions, such as nitrate, can bind to these chloride binding sites, however, their ability to allosterically activate salivary amylase is much weaker.

	== Evolutionary Relationship ==		== Evolutionary Relationship ==

Sam Himstedt at 22:29, 28 April 2022

Sam Himstedt — Thu, 28 Apr 2022 22:29:01 GMT

←Older revision		Revision as of 22:29, 28 April 2022
Line 13:		Line 13:

	== Ligands ==		== Ligands ==
-	Human salivary amylase has two ligands, calcium and chlorine. There are three metal binding sites per domain that bind calcium <ref name="pdb">DOI:10.2210/pdb1SMD/pdb</ref>. Studies that have investigated the function of these calcium ions have suggested that the presence of these ions greatly influences the thermostability of the enzyme <ref name="cal">DOI:10.2174/0929866526666190116162958</ref>. This may be a result of the fact that the enzyme moves from the cooler oral cavity to warmer regions of the gastrointestinal tract; however, the lower pH of these regions may inactivate salivary amylase. These metal binding sites occur at the <scene name='91/910719/Cal1/2'>asparagine residue at position 100</scene>, the <scene name='91/910719/Cal2/2'>arginine residue at position 158</scene>, the <scene name='91/910719/Cal3/2'>glutamate residue at position 167</scene>, and the <scene name='91/910719/Cal4/1'>histidine residue at position 201</scene>. Aside from calcium, chloride ions can bind to salivary amylase and there are three binding sites for this ligand <ref name="pdb"/>. These chloride binding sites are found at the <scene name='91/910719/Cl1/1'>arginine residue at position 195</scene>, the <scene name='91/910719/Cl2/1'>asparagine residue at position 298</scene>, and the arginine residue at position 337. It is suggested that the negative charge associated with these chloride ions is essential for the maximal catalytic activity of the enzyme <ref name="chl">DOI:10.1110/ps.0202602</ref>. Other ions, such as nitrate, can bind to these chloride binding sites, however, their ability to allosterically activate salivary amylase is much weaker.	+	Human salivary amylase has two ligands, calcium and chlorine. There are three metal binding sites per domain that bind calcium <ref name="pdb">DOI:10.2210/pdb1SMD/pdb</ref>. Studies that have investigated the function of these calcium ions have suggested that the presence of these ions greatly influences the thermostability of the enzyme <ref name="cal">DOI:10.2174/0929866526666190116162958</ref>. This may be a result of the fact that the enzyme moves from the cooler oral cavity to warmer regions of the gastrointestinal tract; however, the lower pH of these regions may inactivate salivary amylase. These metal binding sites occur at the <scene name='91/910719/Cal1/2'>asparagine residue at position 100</scene>, the <scene name='91/910719/Cal2/2'>arginine residue at position 158</scene>, the <scene name='91/910719/Cal3/2'>glutamate residue at position 167</scene>, and the <scene name='91/910719/Cal4/1'>histidine residue at position 201</scene>. Aside from calcium, chloride ions can bind to salivary amylase and there are three binding sites for this ligand <ref name="pdb"/>. These chloride binding sites are found at the <scene name='91/910719/Cl1/1'>arginine residue at position 195</scene>, the <scene name='91/910719/Cl2/1'>asparagine residue at position 298</scene>, and the <scene name='91/910719/Cl3/1'>arginine residue at position 337</scene>. It is suggested that the negative charge associated with these chloride ions is essential for the maximal catalytic activity of the enzyme <ref name="chl">DOI:10.1110/ps.0202602</ref>. Other ions, such as nitrate, can bind to these chloride binding sites, however, their ability to allosterically activate salivary amylase is much weaker.

	== Evolutionary Relationship ==		== Evolutionary Relationship ==

Sam Himstedt at 22:25, 28 April 2022

Sam Himstedt — Thu, 28 Apr 2022 22:25:27 GMT

←Older revision		Revision as of 22:25, 28 April 2022
Line 13:		Line 13:

	== Ligands ==		== Ligands ==
-	Human salivary amylase has two ligands, calcium and chlorine. There are three metal binding sites per domain that bind calcium <ref name="pdb">DOI:10.2210/pdb1SMD/pdb</ref>. Studies that have investigated the function of these calcium ions have suggested that the presence of these ions greatly influences the thermostability of the enzyme <ref name="cal">DOI:10.2174/0929866526666190116162958</ref>. This may be a result of the fact that the enzyme moves from the cooler oral cavity to warmer regions of the gastrointestinal tract; however, the lower pH of these regions may inactivate salivary amylase. These metal binding sites occur at the <scene name='91/910719/Cal1/2'>asparagine residue at position 100</scene>, the <scene name='91/910719/Cal2/2'>arginine residue at position 158</scene>, the <scene name='91/910719/Cal3/2'>glutamate residue at position 167</scene>, and the <scene name='91/910719/Cal4/1'>histidine residue at position 201</scene>. Aside from calcium, chloride ions can bind to salivary amylase and there are three binding sites for this ligand <ref name="pdb"/>. These chloride binding sites are found at the <scene name='91/910719/Cl1/1'>arginine residue at position 195</scene>, the asparagine residue at position 298, and the arginine residue at position 337. It is suggested that the negative charge associated with these chloride ions is essential for the maximal catalytic activity of the enzyme <ref name="chl">DOI:10.1110/ps.0202602</ref>. Other ions, such as nitrate, can bind to these chloride binding sites, however, their ability to allosterically activate salivary amylase is much weaker.	+	Human salivary amylase has two ligands, calcium and chlorine. There are three metal binding sites per domain that bind calcium <ref name="pdb">DOI:10.2210/pdb1SMD/pdb</ref>. Studies that have investigated the function of these calcium ions have suggested that the presence of these ions greatly influences the thermostability of the enzyme <ref name="cal">DOI:10.2174/0929866526666190116162958</ref>. This may be a result of the fact that the enzyme moves from the cooler oral cavity to warmer regions of the gastrointestinal tract; however, the lower pH of these regions may inactivate salivary amylase. These metal binding sites occur at the <scene name='91/910719/Cal1/2'>asparagine residue at position 100</scene>, the <scene name='91/910719/Cal2/2'>arginine residue at position 158</scene>, the <scene name='91/910719/Cal3/2'>glutamate residue at position 167</scene>, and the <scene name='91/910719/Cal4/1'>histidine residue at position 201</scene>. Aside from calcium, chloride ions can bind to salivary amylase and there are three binding sites for this ligand <ref name="pdb"/>. These chloride binding sites are found at the <scene name='91/910719/Cl1/1'>arginine residue at position 195</scene>, the <scene name='91/910719/Cl2/1'>asparagine residue at position 298</scene>, and the arginine residue at position 337. It is suggested that the negative charge associated with these chloride ions is essential for the maximal catalytic activity of the enzyme <ref name="chl">DOI:10.1110/ps.0202602</ref>. Other ions, such as nitrate, can bind to these chloride binding sites, however, their ability to allosterically activate salivary amylase is much weaker.

	== Evolutionary Relationship ==		== Evolutionary Relationship ==

Sam Himstedt at 22:21, 28 April 2022

Sam Himstedt — Thu, 28 Apr 2022 22:21:31 GMT

←Older revision		Revision as of 22:21, 28 April 2022
Line 13:		Line 13:

	== Ligands ==		== Ligands ==
-	Human salivary amylase has two ligands, calcium and chlorine. There are three metal binding sites per domain that bind calcium <ref name="pdb">DOI:10.2210/pdb1SMD/pdb</ref>. Studies that have investigated the function of these calcium ions have suggested that the presence of these ions greatly influences the thermostability of the enzyme <ref name="cal">DOI:10.2174/0929866526666190116162958</ref>. This may be a result of the fact that the enzyme moves from the cooler oral cavity to warmer regions of the gastrointestinal tract; however, the lower pH of these regions may inactivate salivary amylase. These metal binding sites occur at the <scene name='91/910719/Cal1/2'>asparagine residue at position 100</scene>, the <scene name='91/910719/Cal2/2'>arginine residue at position 158</scene>, the <scene name='91/910719/Cal3/2'>glutamate residue at position 167</scene>, and the <scene name='91/910719/Cal4/1'>histidine residue at position 201</scene>. Aside from calcium, chloride ions can bind to salivary amylase and there are three binding sites for this ligand <ref name="pdb"/>. These chloride binding sites are found at the arginine residue at position 195, the asparagine residue at position 298, and the arginine residue at position 337. It is suggested that the negative charge associated with these chloride ions is essential for the maximal catalytic activity of the enzyme <ref name="chl">DOI:10.1110/ps.0202602</ref>. Other ions, such as nitrate, can bind to these chloride binding sites, however, their ability to allosterically activate salivary amylase is much weaker.	+	Human salivary amylase has two ligands, calcium and chlorine. There are three metal binding sites per domain that bind calcium <ref name="pdb">DOI:10.2210/pdb1SMD/pdb</ref>. Studies that have investigated the function of these calcium ions have suggested that the presence of these ions greatly influences the thermostability of the enzyme <ref name="cal">DOI:10.2174/0929866526666190116162958</ref>. This may be a result of the fact that the enzyme moves from the cooler oral cavity to warmer regions of the gastrointestinal tract; however, the lower pH of these regions may inactivate salivary amylase. These metal binding sites occur at the <scene name='91/910719/Cal1/2'>asparagine residue at position 100</scene>, the <scene name='91/910719/Cal2/2'>arginine residue at position 158</scene>, the <scene name='91/910719/Cal3/2'>glutamate residue at position 167</scene>, and the <scene name='91/910719/Cal4/1'>histidine residue at position 201</scene>. Aside from calcium, chloride ions can bind to salivary amylase and there are three binding sites for this ligand <ref name="pdb"/>. These chloride binding sites are found at the <scene name='91/910719/Cl1/1'>arginine residue at position 195</scene>, the asparagine residue at position 298, and the arginine residue at position 337. It is suggested that the negative charge associated with these chloride ions is essential for the maximal catalytic activity of the enzyme <ref name="chl">DOI:10.1110/ps.0202602</ref>. Other ions, such as nitrate, can bind to these chloride binding sites, however, their ability to allosterically activate salivary amylase is much weaker.

	== Evolutionary Relationship ==		== Evolutionary Relationship ==

Sam Himstedt at 22:15, 28 April 2022

Sam Himstedt — Thu, 28 Apr 2022 22:15:15 GMT

←Older revision		Revision as of 22:15, 28 April 2022
Line 13:		Line 13:

	== Ligands ==		== Ligands ==
-	Human salivary amylase has two ligands, calcium and chlorine. There are three metal binding sites per domain that bind calcium <ref name="pdb">DOI:10.2210/pdb1SMD/pdb</ref>. Studies that have investigated the function of these calcium ions have suggested that the presence of these ions greatly influences the thermostability of the enzyme <ref name="cal">DOI:10.2174/0929866526666190116162958</ref>. This may be a result of the fact that the enzyme moves from the cooler oral cavity to warmer regions of the gastrointestinal tract; however, the lower pH of these regions may inactivate salivary amylase. These metal binding sites occur at the <scene name='91/910719/Cal1/2'>asparagine residue at position 100</scene>, the <scene name='91/910719/Cal2/2'>arginine residue at position 158</scene>, the <scene name='91/910719/Cal3/1'>glutamate residue at position 167</scene>, and the <scene name='91/910719/Cal4/1'>histidine residue at position 201</scene>. Aside from calcium, chloride ions can bind to salivary amylase and there are three binding sites for this ligand <ref name="pdb"/>. These chloride binding sites are found at the arginine residue at position 195, the asparagine residue at position 298, and the arginine residue at position 337. It is suggested that the negative charge associated with these chloride ions is essential for the maximal catalytic activity of the enzyme <ref name="chl">DOI:10.1110/ps.0202602</ref>. Other ions, such as nitrate, can bind to these chloride binding sites, however, their ability to allosterically activate salivary amylase is much weaker.	+	Human salivary amylase has two ligands, calcium and chlorine. There are three metal binding sites per domain that bind calcium <ref name="pdb">DOI:10.2210/pdb1SMD/pdb</ref>. Studies that have investigated the function of these calcium ions have suggested that the presence of these ions greatly influences the thermostability of the enzyme <ref name="cal">DOI:10.2174/0929866526666190116162958</ref>. This may be a result of the fact that the enzyme moves from the cooler oral cavity to warmer regions of the gastrointestinal tract; however, the lower pH of these regions may inactivate salivary amylase. These metal binding sites occur at the <scene name='91/910719/Cal1/2'>asparagine residue at position 100</scene>, the <scene name='91/910719/Cal2/2'>arginine residue at position 158</scene>, the <scene name='91/910719/Cal3/2'>glutamate residue at position 167</scene>, and the <scene name='91/910719/Cal4/1'>histidine residue at position 201</scene>. Aside from calcium, chloride ions can bind to salivary amylase and there are three binding sites for this ligand <ref name="pdb"/>. These chloride binding sites are found at the arginine residue at position 195, the asparagine residue at position 298, and the arginine residue at position 337. It is suggested that the negative charge associated with these chloride ions is essential for the maximal catalytic activity of the enzyme <ref name="chl">DOI:10.1110/ps.0202602</ref>. Other ions, such as nitrate, can bind to these chloride binding sites, however, their ability to allosterically activate salivary amylase is much weaker.

	== Evolutionary Relationship ==		== Evolutionary Relationship ==