Literature summary for 4.3.1.1 extracted from

Morris, G.A.; Ikumapayi, U.N.; Antonio, M.; Howie, S.R.; Adegbola, R.A.
A novel Campylobacter jejuni sequence type from a culture-negative patient in the Gambia (2008), Mol. Microbiol., 69, 77-93.

Cloned(Commentary)

Cloned (Comment)	Organism
An aspartase mutant 81-176 unable to utilize any amino acid except serine (defective in microaerobic growth on multiple amino acids) and an aspA sdaA double-mutant (also lacking serine dehydratase) is cloned. The aspA gene is cloned into the pET101 expression vector and overexpressed in Escherichia coli BL21	Campylobacter jejuni

Inhibitors

Inhibitors	Comment	Organism	Structure
KCl	aspartase activity is severely inhibited by potassium chloride	Campylobacter jejuni
additional information	enzyme is upregulated by oxygen limitation	Campylobacter jejuni

KM Value [mM]

KM Value [mM]	KM Value Maximum [mM]	Substrate	Comment	Organism
10	-	L-aspartate	pH 6.5, recombinant produced and purified AspA enzyme	Campylobacter jejuni
12.8	-	L-aspartate	pH 7.0, recombinant produced and purified AspA enzyme	Campylobacter jejuni
38.2	-	L-aspartate	pH 8.0, recombinant produced and purified AspA enzyme	Campylobacter jejuni

Metals/Ions

Metals/Ions	Comment	Organism	Structure
Mg2+	aspartase activity is stimulated about 2fold by inclusion of 6 mM magnesium chloride in the assay	Campylobacter jejuni

Natural Substrates/ Products (Substrates)

Natural Substrates	Organism	Comment (Nat. Sub.)	Natural Products	Comment (Nat. Pro.)	Rev.
L-aspartate	Campylobacter jejuni	-	fumarate + NH3	-	?
additional information	Campylobacter jejuni	aspartate enhances oxygen-limited strain growth via fumarate respiration in an aspA-dependent manner	?	-	?
additional information	Campylobacter jejuni	both wild-type and AspA mutant Campylobacter jejuni strains show similar fumarate-dependent growth	?	-	?

Organism

Organism	UniProt	Comment	Textmining
Campylobacter jejuni	Q0PC50	Cj0087; zoonotic pathogen, a number of avian species are reservoirs for this organism	-

Oxidation Stability

Oxidation Stability	Organism
over 24 h of microaerobic batch growth, the AspA specific enzyme activity increases 10fold and the relative abundance of the protein increases over 13fold. After transferring initially microaerobic cultures to oxygenlimiting conditions in the absence of an added electron acceptor, there is an immediate cessation of growth but an approximately 3fold rise in AspA specific activity up to 24 h correlated with a smaller increase in the abundance of the protein.	Campylobacter jejuni

Organism

over 24 h of microaerobic batch growth, the AspA specific enzyme activity increases 10fold and the relative abundance of the protein increases over 13fold. After transferring initially microaerobic cultures to oxygenlimiting conditions in the absence of an added electron acceptor, there is an immediate cessation of growth but an approximately 3fold rise in AspA specific activity up to 24 h correlated with a smaller increase in the abundance of the protein.

Campylobacter jejuni

Purification (Commentary)

Purification (Comment)	Organism
After overexpression of the aspA gene in Escherichia coli BL21, the gene product is purified to homogeneity by ion-exchange and hydrophobic interaction chromatography	Campylobacter jejuni

Source Tissue

Source Tissue	Comment	Organism	Textmining
cell culture	strain NCTC 11168	Campylobacter jejuni	-

Specific Activity [micromol/min/mg]

Specific Activity Minimum [µmol/min/mg]	Specific Activity Maximum [µmol/min/mg]	Comment	Organism
additional information	-	AspA has a role in the persistence of Campylobacter jejuni in the avian intestine	Campylobacter jejuni
additional information	-	aspA mutant strain is totally deficient in aspartase enzyme activity, whereas in the wild-type enzyme, an extremely high specific activity is present in stationary-phase cell-free extracts (more than 2 mmol fumarate are produced per min per mg protein)	Campylobacter jejuni
0.23	-	strain 81-176 aspA mutant	Campylobacter jejuni
2.06	-	wild-type aspartase activity, spectrophotometric assay in cell-free extracts from cells grown to early stationary phase in BHI-FCS medium	Campylobacter jejuni
93.7	-	at pH 6.5, recombinant produced and purified AspA enzyme	Campylobacter jejuni
119.7	-	at pH 7.0, recombinant produced and purified AspA enzyme	Campylobacter jejuni
191	-	at pH 8.0, recombinant produced and purified AspA enzyme	Campylobacter jejuni

Substrates and Products (Substrate)

Substrates	Comment Substrates	Organism	Products	Comment (Products)	Rev.
L-aspartate	-	Campylobacter jejuni	fumarate + NH3	-	?
additional information	aspartate enhances oxygen-limited strain growth via fumarate respiration in an aspA-dependent manner	Campylobacter jejuni	?	-	?
additional information	both wild-type and AspA mutant Campylobacter jejuni strains show similar fumarate-dependent growth	Campylobacter jejuni	?	-	?

Synonyms

Synonyms	Comment	Organism
ASPA	-	Campylobacter jejuni
aspartase	-	Campylobacter jejuni
aspartate:ammonia lyase	reverse reaction	Campylobacter jejuni
Cj0087	-	Campylobacter jejuni

Temperature Optimum [°C]

Temperature Optimum [°C]	Temperature Optimum Maximum [°C]	Comment	Organism
37	-	assay at	Campylobacter jejuni

pH Optimum

pH Optimum Minimum	pH Optimum Maximum	Comment	Organism
8	-	-	Campylobacter jejuni