English
 
Help Privacy Policy Disclaimer
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT
 
 
DownloadE-Mail
  Structures of apo and product-bound human L-asparaginase: Insights into the mechanism of autoproteolysis and substrate hydrolysis.

Nomme, J., Su, Y., Konrad, M., & Lavie, A. (2012). Structures of apo and product-bound human L-asparaginase: Insights into the mechanism of autoproteolysis and substrate hydrolysis. Biochemistry, 51(34), 6816-6826. doi:10.1021/bi300870g.

Item is

Files

show Files
hide Files
:
1542251.pdf (Publisher version), 677KB
 
File Permalink:
-
Name:
1542251.pdf
Description:
-
OA-Status:
Visibility:
Restricted (UNKNOWN id 303; )
MIME-Type / Checksum:
application/pdf
Technical Metadata:
Copyright Date:
-
Copyright Info:
-
License:
-
:
1542251_si_001.pdf (Publisher version), 615KB
Name:
1542251_si_001.pdf
Description:
-
OA-Status:
Visibility:
Public
MIME-Type / Checksum:
application/pdf / [MD5]
Technical Metadata:
Copyright Date:
-
Copyright Info:
-
License:
-

Locators

show
hide
Description:
-
OA-Status:

Creators

show
hide
 Creators:
Nomme, J., Author
Su, Y., Author
Konrad, M.1, Author           
Lavie, A., Author
Affiliations:
1Research Group of Enzyme Biochemistry, MPI for biophysical chemistry, Max Planck Society, ou_578612              

Content

show
hide
Free keywords: -
 Abstract: Asparaginases catalyze the hydrolysis of the amino acid asparagine to aspartate and ammonia. Bacterial asparaginases are used in cancer chemotherapy to deplete asparagine from the blood, because several hematological malignancies depend on extracellular asparagine for growth. To avoid the immune response against the bacterial enzymes, it would be beneficial to replace them with human asparaginases. However, unlike the bacterial asparaginases, the human enzymes have a millimolar K-m value for asparagine, making them inefficient in depleting the amino acid from blood. To facilitate the development of human variants suitable for therapeutic use, we determined the structure of human L-asparaginase (hASNase3). This asparaginase is an N-terminal nucleophile (Ntn) family member that requires autocleavage between Gly167 and Thr168 to become catalytically competent For most Ntn hydrolases, this autoproteolytic activation occurs efficiently. In contrast, hASNas3 is relatively Stable in its uncleaved state, and this allowed us to observe the structure of the enzyme prior to cleavage. To determine the structure of the cleaved state; we exploited our discovery that the free amino acid glycine promotes complete cleavage of hASNase3: Both enzyme states were elucidated in the absence and presence of the product aspartate. Together, these structures provide insight into the conformational changes required for Cleavage and the precise enzyme-substrate interactions. The new Understanding of hASNase3 will serve to guide the design of variants that possess a decreased K-m value for asparagine, making the human enzyme a suitable replacement for the bacterial asparaginases in cancer therapy.

Details

show
hide
Language(s): eng - English
 Dates: 2012-08-032012-08-28
 Publication Status: Issued
 Pages: -
 Publishing info: -
 Table of Contents: -
 Rev. Type: Peer
 Identifiers: DOI: 10.1021/bi300870g
 Degree: -

Event

show

Legal Case

show

Project information

show

Source 1

show
hide
Title: Biochemistry
Source Genre: Journal
 Creator(s):
Affiliations:
Publ. Info: -
Pages: - Volume / Issue: 51 (34) Sequence Number: - Start / End Page: 6816 - 6826 Identifier: -