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This is the Wikipedia entry entitled "Asparaginase". More...
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Asparaginase Edit Wikipedia article
|Systematic (IUPAC) name|
|E. coli L-asparagine amidohydrolase|
|Licence data||US FDA:|
|Routes||IM or IV|
|Half-life||39-49 hours (IM), 8-30 hours (IV)|
|Mol. mass||31731.9 g/mol|
|(what is this?)|
Asparaginase (EC 18.104.22.168, USAN) or Colaspase (BAN) is an enzyme that catalyzes the hydrolysis of asparagine to aspartic acid. Asparaginases are naturally occurring enzymes expressed and produced by microorganisms.
It is on the World Health Organization's List of Essential Medicines, a list of the most important medication needed in a basic health system.
Different types of asparaginases can be used for different industrial and pharmaceutical purposes.
A different asparaginase is marketed as a drug under the brand name Elspar for the treatment of acute lymphoblastic leukemia (ALL) and is also used in some mast cell tumor protocols. Unlike most of other chemotherapy agents, it can be given as an intramuscular, subcutaneous, or intravenous injection without fear of tissue irritation.
The most common use of asparaginases is as a processing aid in the manufacture of food. Marketed under the brand names Acrylaway and PreventASe, asparaginases are used as a food processing aid to reduce the formation of acrylamide, a suspected carcinogen, in starchy food products such as snacks and biscuits.
The main side effect is an allergic or hypersensitivity reaction; anaphylaxis is a possibility. Additionally, it can also be associated with a coagulopathy as it decreases protein synthesis, including synthesis of coagulation factors (e.g. progressive isolated decrease of fibrinogen) and anticoagulant factor (generally antithrombin III; sometimes protein C & S as well), leading to bleeding or thrombotic events such as stroke. Bone marrow suppression is common but only mild to moderate, rarely reaches clinical significance and therapeutic consequences are rarely required.
Other common side effects include pancreatitis.
Mechanism of action
As a food processing aid
Acrylamide is often formed in starchy foods when they are baked or fried. During heating the amino acid asparagine, naturally present in starchy foods, undergoes a process called the Maillard reaction, which is responsible for giving baked or fried foods their brown color, crust and toasted flavor. Unfortunately, suspected carcinogens such as acrylamide and some heterocyclic amines are also formed in the Maillard reaction.
By adding asparaginase before baking or frying the food, asparagine is converted into another common amino acid, aspartic acid, and ammonium ions. As a result, asparagine cannot take part in the Maillard reaction, and therefore the formation of acrylamide is significantly reduced. Complete acrylamide removal is probably not possible due to other, minor asparagine-independent formation pathways.
As a food processing aid, asparaginases can effectively reduce the level of acrylamide up to 90% in a range of starchy foods without changing the taste and appearance of the end product.
As a drug
The rationale behind asparaginase is that it takes advantage of the fact that ALL leukemic cells and some other suspected tumor cells are unable to synthesize the non-essential amino acid asparagine, whereas normal cells are able to make their own asparagine; thus leukemic cells require high amount of asparagine. These leukemic cells depend on circulating asparagine. Asparaginase, however, catalyzes the conversion of L-asparagine to aspartic acid and ammonia. This deprives the leukemic cell of circulating asparagine, which leads to cell death.
The discovery and development of asparaginase as an anti-cancer drug began in 1953, when scientists first observed that lymphomas in rat and mice regressed after treatment with guinea pig serum. Later it was found out that it is not the serum itself which provoke the tumour regression, but rather the enzyme asparaginase.
After researches comparing different kinds of asparaginases, the one derived from Escherichia coli and Erwinia chrysanthemi turned out to have the best anti-cancer ability. E. coli has thereby become the main source of asparaginase due to the factor that it is also easy to produce in large amount. Asparaginase produced by Erwinia chrysanthemi instead is known as crisantaspase (BAN), and is available in the United Kingdom under the trade name Erwinase.
- H. Geckil and S. Gencer. (2004). "Production of L-asparaginase in Enterobacter aerogenes expressing Vitreoscilla hemoglobin for efficient oxygen uptake.". Appl. Microbiol. Biotechnol. 63 (6): 691–97. doi:10.1007/s00253-003-1482-5. PMID 14593509.
- "WHO Model List of EssentialMedicines". World Health Organization. October 2013. Retrieved 22 April 2014.
- "8.1.5: Other antineoplastic drugs". British National Formulary (BNF 57). United Kingdom: BMJ Group and RPS Publishing. March 2009. p. 476. ISBN 978-0-85369-845-6.
- Appel IM, van Kessel-Bakvis C, Stigter R, Pieters R (2007). "Influence of two different regimens of concomitant treatment with asparaginase and dexamethason] on hemostasis in childhood acute lymphoblastic leukemia". Leukemia 21 (11): 2377–80. doi:10.1038/sj.leu.2404793. PMID 17554375.
- Kornbrust, B.A., Stringer, M.A., Lange, N.K. and Hendriksen, H.V. (2010) Asparaginase – an enzyme for acrylamide reduction in food products. In: Enzymes in Food Technology, 2nd Edition. (eds Robert J. Whitehurst and Maarten Van Oort). Wiley-Blackwell, UK, pp. 59-87.
- Müller, H. (1998). "Use of L-asparaginase in childhood ALL". Critical Reviews in Oncology/Hematology 28 (2): 97–11. doi:10.1016/S1040-8428(98)00015-8.
- Johnston, P. G.; Hardisty, R. M.; Kay, H. E.; Smith, P. G. (1974). "Myelosuppressive effect of colaspase (L-asparaginase) in initial treatment of acute lymphoblastic leukaemia". British medical journal 3 (5923): 81–83. doi:10.1136/bmj.3.5923.81. PMC 1611087. PMID 4604804.
- Hendriksen, H.V.; Kornbrust, B.A.; Oestergaard, P.R.; Stringer, M.A. (April 23, 2009). "Evaluating the Potential for Enzymatic Acrylamide Mitigation in a Range of Food Products Using an Asparaginase from Aspergillus oryzae". Journal of Agricultural and Food Chemistry 57 (10): 4168–4176. doi:10.1021/jf900174q. PMID 19388639. Retrieved October 8, 2010.
- Broome, J. D. (1981). "L-Asparaginase: Discovery and development as a tumor-inhibitory agent". Cancer treatment reports. 65 Suppl 4: 111–114. PMID 7049374.
- T. Selwood and E. K. Jaffe. (2011). "Dynamic dissociating homo-oligomers and the control of protein function.". Arch. Biochem. Biophys. 519 (2): 131–43. doi:10.1016/j.abb.2011.11.020. PMC 3298769. PMID 22182754.
- Kidd, J. G. (1953). "Regression of transplanted lymphomas induced in vivo by means of normal guinea pig serum. I. Course of transplanted cancers of various kinds in mice and rats given guinea pig serum, horse serum, or rabbit serum". The Journal of experimental medicine 98 (6): 565–582. doi:10.1084/jem.98.6.565. PMC 2136344. PMID 13109110.
- Broome, J. D. (1963). "Evidence that the L-asparaginase of guinea pig serum is responsible for its antilymphoma effects. I. Properties of the L-asparaginase of guinea pig serum in relation to those of the antilymphoma substance". The Journal of experimental medicine 118 (1): 99–120. doi:10.1084/jem.118.1.99. PMC 2137570. PMID 14015821.
- Eukaryotic Linear Motif resource motif class CLV_TASPASE1
- Asparaginase at the US National Library of Medicine Medical Subject Headings (MeSH)
- Crisantaspase information from Macmillan Cancer Support
- U.S. NLM, NIH Drug Information Portal - Asparaginase
This tab holds the annotation information that is stored in the Pfam database. As we move to using Wikipedia as our main source of annotation, the contents of this tab will be gradually replaced by the Wikipedia tab.
Asparaginase Provide feedback
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External database links
This tab holds annotation information from the InterPro database.
InterPro entry IPR000246
In the MEROPS database peptidases and peptidase homologues are grouped into clans and families. Clans are groups of families for which there is evidence of common ancestry based on a common structural fold:
- Each clan is identified with two letters, the first representing the catalytic type of the families included in the clan (with the letter 'P' being used for a clan containing families of more than one of the catalytic types serine, threonine and cysteine). Some families cannot yet be assigned to clans, and when a formal assignment is required, such a family is described as belonging to clan A-, C-, M-, N-, S-, T- or U-, according to the catalytic type. Some clans are divided into subclans because there is evidence of a very ancient divergence within the clan, for example MA(E), the gluzincins, and MA(M), the metzincins.
- Peptidase families are grouped by their catalytic type, the first character representing the catalytic type: A, aspartic; C, cysteine; G, glutamic acid; M, metallo; N, asparagine; S, serine; T, threonine; and U, unknown. The serine, threonine and cysteine peptidases utilise the amino acid as a nucleophile and form an acyl intermediate - these peptidases can also readily act as transferases. In the case of aspartic, glutamic and metallopeptidases, the nucleophile is an activated water molecule. In the case of the asparagine endopeptidases, the nucleophile is asparagine and all are self-processing endopeptidases.
In many instances the structural protein fold that characterises the clan or family may have lost its catalytic activity, yet retain its function in protein recognition and binding.
Threonine peptidases are characterised by a threonine nucleophile at the N terminus of the mature enzyme. The threonine peptidases belong to clan PB or are unassigned, clan T-. The type example for this clan is the archaean proteasome beta component of Thermoplasma acidophilum.
This group of sequences have a signature that places them in MEROPS peptidase family T2 (clan PB(T)). The glycosylasparaginases (EC) are threonine peptidases. Also in this family is L-asparaginase (EC), which catalyses the following reaction:
The mapping between Pfam and Gene Ontology is provided by InterPro. If you use this data please cite InterPro.
|Molecular function||hydrolase activity (GO:0016787)|
Below is a listing of the unique domain organisations or architectures in which this domain is found. More...
The graphic that is shown by default represents the longest sequence with a given architecture. Each row contains the following information:
- the number of sequences which exhibit this architecture
a textual description of the architecture, e.g. Gla, EGF x 2, Trypsin.
This example describes an architecture with one
Gladomain, followed by two consecutive
EGFdomains, and finally a single
- a link to the page in the Pfam site showing information about the sequence that the graphic describes
- the UniProt description of the protein sequence
- the number of residues in the sequence
- the Pfam graphic itself.
Note that you can see the family page for a particular domain by clicking on the graphic. You can also choose to see all sequences which have a given architecture by clicking on the Show link in each row.
Finally, because some families can be found in a very large number of architectures, we load only the first fifty architectures by default. If you want to see more architectures, click the button at the bottom of the page to load the next set.
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In the N-terminal nucleophile aminohydrolases (Ntn hydrolases) the N-terminal residue provides two catalytic groups, nucleophile and proton donor. These enzymes use the side chain of the amino-terminal residue, incorporated in a beta-sheet, as the nucleophile in the catalytic attack at the carbonyl carbon. The nucleophile is cysteine in GAT, serine in penicillin acylase, and threonine in the proteasome. All the enzymes share an unusual fold in which the nucleophile and other catalytic groups occupy equivalent sites. This fold provides both the capacity for nucleophilic attack and the possibility of autocatalytic processing .
The clan contains the following 14 members:AAT Asparaginase_2 CBAH DUF1933 DUF3700 G_glu_transpept GATase_2 GATase_4 GATase_6 GATase_7 Penicil_amidase Peptidase_C69 Phospholip_B Proteasome
We store a range of different sequence alignments for families. As well as the seed alignment from which the family is built, we provide the full alignment, generated by searching the sequence database using the family HMM. We also generate alignments using four representative proteomes (RP) sets, the NCBI sequence database, and our metagenomics sequence database. More...
There are various ways to view or download the sequence alignments that we store. We provide several sequence viewers and a plain-text Stockholm-format file for download.
We make a range of alignments for each Pfam-A family:
- the curated alignment from which the HMM for the family is built
- the alignment generated by searching the sequence database using the HMM
- Representative Proteomes (RPs) at 15%, 35%, 55% and 75% co-membership thresholds
- alignment generated by searching the NCBI sequence database using the family HMM
- alignment generated by searching the metagenomics sequence database using the family HMM
You can see the alignments as HTML or in three different sequence viewers:
- a Java applet developed at the University of Dundee. You will need Java installed before running jalview
- an HTML page showing the whole alignment.Please note: full Pfam alignments can be very large. These HTML views are extremely large and often cause problems for browsers. Please use either jalview or the Pfam viewer if you have trouble viewing the HTML version
- an HTML-based representation of the alignment, coloured according to the posterior-probability (PP) values from the HMM. As for the standard HTML view, heatmap alignments can also be very large and slow to render.
- Pfam viewer
- an HTML-based viewer that uses DAS to retrieve alignment fragments on request
You can download (or view in your browser) a text representation of a Pfam alignment in various formats:
You can also change the order in which sequences are listed in the alignment, change how insertions are represented, alter the characters that are used to represent gaps in sequences and, finally, choose whether to download the alignment or to view it in your browser directly.
You may find that large alignments cause problems for the viewers and the reformatting tool, so we also provide all alignments in Stockholm format. You can download either the plain text alignment, or a gzipped version of it.
We make a range of alignments for each Pfam-A family. You can see a description of each above. You can view these alignments in various ways but please note that some types of alignment are never generated while others may not be available for all families, most commonly because the alignments are too large to handle.
1Cannot generate PP/Heatmap alignments for seeds; no PP data available
Key: available, not generated, — not available.
Format an alignment
We make all of our alignments available in Stockholm format. You can download them here as raw, plain text files or as gzip-compressed files.
You can also download a FASTA format file containing the full-length sequences for all sequences in the full alignment.
MyHits provides a collection of tools to handle multiple sequence alignments. For example, one can refine a seed alignment (sequence addition or removal, re-alignment or manual edition) and then search databases for remote homologs using HMMER3.
HMM logos is one way of visualising profile HMMs. Logos provide a quick overview of the properties of an HMM in a graphical form. You can see a more detailed description of HMM logos and find out how you can interpret them here. More...
If you find these logos useful in your own work, please consider citing the following article:
This page displays the phylogenetic tree for this family's seed alignment. We use FastTree to calculate neighbour join trees with a local bootstrap based on 100 resamples (shown next to the tree nodes). FastTree calculates approximately-maximum-likelihood phylogenetic trees from our seed alignment.
Note: You can also download the data file for the tree.
Curation and family details
This section shows the detailed information about the Pfam family. You can see the definitions of many of the terms in this section in the glossary and a fuller explanation of the scoring system that we use in the scores section of the help pages.
|Seed source:||Sarah Teichmann|
|Number in seed:||7|
|Number in full:||2653|
|Average length of the domain:||259.80 aa|
|Average identity of full alignment:||32 %|
|Average coverage of the sequence by the domain:||88.17 %|
|HMM build commands:||
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 23193494 -E 1000 --cpu 4 HMM pfamseq
|Family (HMM) version:||13|
|Download:||download the raw HMM for this family|
Weight segments by...
Change the size of the sunburst
selected sequences to HMM
a FASTA-format file
- 0 sequences
- 0 species
This visualisation provides a simple graphical representation of the distribution of this family across species. You can find the original interactive tree in the More....
This chart is a modified "sunburst" visualisation of the species tree for this family. It shows each node in the tree as a separate arc, arranged radially with the superkingdoms at the centre and the species arrayed around the outermost ring.
How the sunburst is generated
The tree is built by considering the taxonomic lineage of each sequence that has a match to this family. For each node in the resulting tree, we draw an arc in the sunburst. The radius of the arc, its distance from the root node at the centre of the sunburst, shows the taxonomic level ("superkingdom", "kingdom", etc). The length of the arc represents either the number of sequences represented at a given level, or the number of species that are found beneath the node in the tree. The weighting scheme can be changed using the sunburst controls.
In order to reduce the complexity of the representation, we reduce the number of taxonomic levels that we show. We consider only the following eight major taxonomic levels:
Colouring and labels
Segments of the tree are coloured approximately according to their superkingdom. For example, archeal branches are coloured with shades of orange, eukaryotes in shades of purple, etc. The colour assignments are shown under the sunburst controls. Where space allows, the name of the taxonomic level will be written on the arc itself.
As you move your mouse across the sunburst, the current node will be highlighted. In the top section of the controls panel we show a summary of the lineage of the currently highlighed node. If you pause over an arc, a tooltip will be shown, giving the name of the taxonomic level in the title and a summary of the number of sequences and species below that node in the tree.
Anomalies in the taxonomy tree
There are some situations that the sunburst tree cannot easily handle and for which we have work-arounds in place.
Missing taxonomic levels
Some species in the taxonomic tree may not have one or more of the main eight levels that we display. For example, Bos taurus is not assigned an order in the NCBI taxonomic tree. In such cases we mark the omitted level with, for example, "No order", in both the tooltip and the lineage summary.
Unmapped species names
The tree is built by looking at each sequence in the full alignment for the family. We take the name of the species given by UniProt and try to map that to the full taxonomic tree from NCBI. In some cases, the name chosen by UniProt does not map to any node in the NCBI tree, perhaps because the chosen name is listed as a synonym or a misspelling in the NCBI taxonomy.
So that these nodes are not simply omitted from the sunburst tree, we group them together in a separate branch (or segment of the sunburst tree). Since we cannot determine the lineage for these unmapped species, we show all levels between the superkingdom and the species as "uncategorised".
Since we reduce the species tree to only the eight main taxonomic levels, sequences that are mapped to the sub-species level in the tree would not normally be shown. Rather than leave out these species, we map them instead to their parent species. So, for example, for sequences belonging to one of the Vibrio cholerae sub-species in the NCBI taxonomy, we show them instead as belonging to the species Vibrio cholerae.
Too many species/sequences
For large species trees, you may see blank regions in the outer layers of the sunburst. These occur when there are large numbers of arcs to be drawn in a small space. If an arc is less than approximately one pixel wide, it will not be drawn and the space will be left blank. You may still be able to get some information about the species in that region by moving your mouse across the area, but since each arc will be very small, it will be difficult to accurately locate a particular species.
The tree shows the occurrence of this domain across different species. More...
We show the species tree in one of two ways. For smaller trees we try to show an interactive representation, which allows you to select specific nodes in the tree and view them as an alignment or as a set of Pfam domain graphics.
Unfortunately we have found that there are problems viewing the interactive tree when the it becomes larger than a certain limit. Furthermore, we have found that Internet Explorer can become unresponsive when viewing some trees, regardless of their size. We therefore show a text representation of the species tree when the size is above a certain limit or if you are using Internet Explorer to view the site.
If you are using IE you can still load the interactive tree by clicking the "Generate interactive tree" button, but please be aware of the potential problems that the interactive species tree can cause.
For all of the domain matches in a full alignment, we count the number that are found on all sequences in the alignment. This total is shown in the purple box.
We also count the number of unique sequences on which each domain is found, which is shown in green. Note that a domain may appear multiple times on the same sequence, leading to the difference between these two numbers.
Finally, we group sequences from the same organism according to the NCBI code that is assigned by UniProt, allowing us to count the number of distinct sequences on which the domain is found. This value is shown in the pink boxes.
We use the NCBI species tree to group organisms according to their taxonomy and this forms the structure of the displayed tree. Note that in some cases the trees are too large (have too many nodes) to allow us to build an interactive tree, but in most cases you can still view the tree in a plain text, non-interactive representation. Those species which are represented in the seed alignment for this domain are highlighted.
You can use the tree controls to manipulate how the interactive tree is displayed:
- show/hide the summary boxes
- highlight species that are represented in the seed alignment
- expand/collapse the tree or expand it to a given depth
- select a sub-tree or a set of species within the tree and view them graphically or as an alignment
- save a plain text representation of the tree
Please note: for large trees this can take some time. While the tree is loading, you can safely switch away from this tab but if you browse away from the family page entirely, the tree will not be loaded.
There is 1 interaction for this family. More...
We determine these interactions using iPfam, which considers the interactions between residues in three-dimensional protein structures and maps those interactions back to Pfam families. You can find more information about the iPfam algorithm in the journal article that accompanies the website.
For those sequences which have a structure in the Protein DataBank, we use the mapping between UniProt, PDB and Pfam coordinate systems from the PDBe group, to allow us to map Pfam domains onto UniProt sequences and three-dimensional protein structures. The table below shows the structures on which the Asparaginase_2 domain has been found. There are 72 instances of this domain found in the PDB. Note that there may be multiple copies of the domain in a single PDB structure, since many structures contain multiple copies of the same protein seqence.
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