Literature summary for 4.2.3.52 extracted from

Savage, T.J.; Hatch, M.W.; Croteau, R.
Monoterpene synthases of Pinus contorta and related conifers. A new class of terpenoid cyclase (1994), J. Biol. Chem., 269, 4012-4020.

Inhibitors

Inhibitors	Comment	Organism	Structure
diethyl dicarbonate	lack of substrate protection against inactivation	Pinus contorta

KM Value [mM]

KM Value [mM]	KM Value Maximum [mM]	Substrate	Comment	Organism	Structure
0.0078	-	geranyl diphosphate	32°C	Pinus contorta

Metals/Ions

Metals/Ions	Comment	Organism
Cs+	activates	Pinus contorta
Fe2+	the enzyme requires either Mn2+ or Fe2+ as divalent metal ion cofactor	Pinus contorta
K+	activates	Pinus contorta
Mn2+	the enzyme requires either Mn2+ or Fe2+ as divalent metal ion cofactor, maximal activity at 1 mM MnCl2	Pinus contorta
additional information	no activation by Mg2+, Li+ or Na+	Pinus contorta
NH4+	activates	Pinus contorta
Rb+	activates	Pinus contorta

Molecular Weight [Da]

Molecular Weight [Da]	Molecular Weight Maximum [Da]	Comment	Organism
67000	-	gel filtration	Pinus contorta

Organism

Organism	UniProt	Comment	Textmining
Pinus contorta	-	-	-

Oxidation Stability

Oxidation Stability	Organism
the enzyme is extremely sensitive to thiol oxidation. Cyclase activity is completely lost when the partially purified xylem preparation is dialyzed against buffer (pH 7.8) devoid of thiol-protecting reagents (dithiothreitol or 2-mercaptoethanol). Other reducing agents, such as sodium ascorbate (5 mM) or sodium metabisulfite (5 mM), fail to protect the cyclases from inactivation, whereas readdition of 5 mM dithiothreitol to the dialyzed preparations restores 54% of the original activity	Pinus contorta

Organism

the enzyme is extremely sensitive to thiol oxidation. Cyclase activity is completely lost when the partially purified xylem preparation is dialyzed against buffer (pH 7.8) devoid of thiol-protecting reagents (dithiothreitol or 2-mercaptoethanol). Other reducing agents, such as sodium ascorbate (5 mM) or sodium metabisulfite (5 mM), fail to protect the cyclases from inactivation, whereas readdition of 5 mM dithiothreitol to the dialyzed preparations restores 54% of the original activity

Pinus contorta

Purification (Commentary)

Purification (Comment)	Organism
-	Pinus contorta

Source Tissue

Source Tissue	Comment	Organism	Textmining
xylem	of 2-year-old Pinus contorta	Pinus contorta	-

Storage Stability

Storage Stability	Organism
0-4°C, partially purified preparation is very stable	Pinus contorta

Substrates and Products (Substrate)

Substrates	Comment Substrates	Organism	Products	Comment (Products)	Rev.	Reac.
geranyl diphosphate	-	Pinus contorta	(4S)-beta-phellandrene + diphosphate	-	?

Subunits

Subunits	Comment	Organism
monomer	1 * 67000, SDS-PAGE	Pinus contorta

Synonyms

Synonyms	Comment	Organism
phellandrene synthase	-	Pinus contorta

pH Optimum

pH Optimum Minimum	pH Optimum Maximum	Comment	Organism
7.8	-	-	Pinus contorta

pH Range

pH Minimum	pH Maximum	Comment	Organism
6.6	8.5	50% of maximal activity at pH 6.6 and at pH 8.5	Pinus contorta

pI Value

Organism	Comment	pI Value Maximum	pI Value
Pinus contorta	isoelectric focusing	-	4.75