This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.

Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.

4o0h

From Proteopedia

(Difference between revisions)

Jump to: navigation, search

Current revision

Crystal structure of human L-asparaginase protein with covalently linked substrate L-asparagine

Structural highlights

4o0h is a 2 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	X-ray diffraction, Resolution 1.97Å
Ligands:	,
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

ASGL1_HUMAN Has both L-asparaginase and beta-aspartyl peptidase activity. May be involved in the production of L-aspartate, which can act as an excitatory neurotransmitter in some brain regions. Is highly active with L-Asp beta-methyl ester. Besides, has catalytic activity toward beta-aspartyl dipeptides and their methyl esters, including beta-L-Asp-L-Phe, beta-L-Asp-L-Phe methyl ester (aspartame), beta-L-Asp-L-Ala, beta-L-Asp-L-Leu and beta-L-Asp-L-Lys. Does not have aspartylglucosaminidase activity and is inactive toward GlcNAc-L-Asn. Likewise, has no activity toward glutamine.^[1]

Publication Abstract from PubMed

Our long-term goal is the design of a human l-asparaginase (hASNase3) variant, suitable for use in cancer therapy without the immunogenicity problems associated with the currently used bacterial enzymes. Asparaginases catalyze the hydrolysis of the amino acid asparagine to aspartate and ammonia. The key property allowing for the depletion of blood asparagine by bacterial asparaginases is their low micromolar KM value. In contrast, human enzymes have a millimolar KM for asparagine. Toward the goal of engineering an hASNase3 variant with micromolar KM, we conducted a structure/function analysis of the conserved catalytic threonine triad of this human enzyme. As a member of the N-terminal nucleophile family, to become enzymatically active, hASNase3 must undergo autocleavage between residues Gly167 and Thr168. To determine the individual contribution of each of the three conserved active-site threonines (threonine triad Thr168, Thr186, Thr219) for the enzyme-activating autocleavage and asparaginase reactions, we prepared the T168S, T186V and T219A/V mutants. These mutants were tested for their ability to cleave and to catalyze asparagine hydrolysis, in addition to being examined structurally. We also elucidated the first N-terminal nucleophile plant-type asparaginase structure in the covalent intermediate state. Our studies indicate that, while not all triad threonines are required for the cleavage reaction, all are essential for the asparaginase activity. The increased understanding of hASNase3 function resulting from these studies reveals the key regions that govern cleavage and the asparaginase reaction, which may inform the design of variants that attain a low KM for asparagine.

Elucidation of the Specific Function of the Conserved Threonine Triad Responsible for Human l-Asparaginase Autocleavage and Substrate Hydrolysis.,Nomme J, Su Y, Lavie A J Mol Biol. 2014 Jun 26;426(13):2471-85. doi: 10.1016/j.jmb.2014.04.016. Epub, 2014 Apr 22. PMID:24768817^[2]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Cantor JR, Stone EM, Chantranupong L, Georgiou G. The human asparaginase-like protein 1 hASRGL1 is an Ntn hydrolase with beta-aspartyl peptidase activity. Biochemistry. 2009 Nov 24;48(46):11026-31. doi: 10.1021/bi901397h. PMID:19839645 doi:10.1021/bi901397h
↑ Nomme J, Su Y, Lavie A. Elucidation of the Specific Function of the Conserved Threonine Triad Responsible for Human l-Asparaginase Autocleavage and Substrate Hydrolysis. J Mol Biol. 2014 Jun 26;426(13):2471-85. doi: 10.1016/j.jmb.2014.04.016. Epub, 2014 Apr 22. PMID:24768817 doi:http://dx.doi.org/10.1016/j.jmb.2014.04.016

1 Structural highlights
2 Function
3 Publication Abstract from PubMed
4 See Also
5 References

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/4o0h"

Categories: Homo sapiens | Large Structures | Lavie A | Nomme J

@@ Line 4: / Line 4: @@
 == Structural highlights ==
 <table><tr><td colspan='2'>[[4o0h]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4O0H OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4O0H FirstGlance]. <br>
-</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=IAS:BETA-L-ASPARTIC+ACID'>IAS</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</scene></td></tr>
+</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.97&#8491;</td></tr>
+<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=IAS:BETA-L-ASPARTIC+ACID'>IAS</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</scene></td></tr>
 <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=4o0h FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4o0h OCA], [https://pdbe.org/4o0h PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4o0h RCSB], [https://www.ebi.ac.uk/pdbsum/4o0h PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4o0h ProSAT]</span></td></tr>
 </table>

4o0h

From Proteopedia

Current revision

Crystal structure of human L-asparaginase protein with covalently linked substrate L-asparagine

Structural highlights

Function

Publication Abstract from PubMed

See Also

References

Contents

Proteopedia Page Contributors and Editors (what is this?)

Views

Personal tools

Navigation

Search

Toolbox