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Binding of nickel to testicular glutamate–ammonia ligase inhibits its enzymatic activity
Author(s) -
Sun Yingbiao,
Ou Young,
Cheng Min,
Ruan Yibing,
van der Hoorn Frans A.
Publication year - 2011
Publication title -
molecular reproduction and development
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.745
H-Index - 105
eISSN - 1098-2795
pISSN - 1040-452X
DOI - 10.1002/mrd.21275
Subject(s) - biology , ammonia , enzyme , dna ligase , glutamate receptor , biochemistry , ubiquitin ligase , nickel , gene , materials science , receptor , ubiquitin , metallurgy
Exposure to nickel has been shown to cause damage to the testis in several animal models. It is not known if the testis expresses protein(s) that can bind nickel. To test this, we used a nickel‐binding assay to isolate testicular nickel‐binding proteins. We identified glutamate–ammonia ligase (GLUL) as a prominent nickel‐binding protein by mass spectrometry. Protein analysis and reverse transcriptase polymerase chain reaction showed that GLUL is expressed in the testis, predominantly in interstitial cells. We determined that GLUL has a higher affinity for nickel than for its regular co‐factor manganese. We produced an enzymatically active, recombinant GLUL protein. Upon binding, nickel interferes with the manganese‐catalyzed enzymatic activity of recombinant GLUL protein. We also determined that GLUL activity in testes of animals exposed to nickel sulfate is reduced. Our results identify testicular GLUL as the first testicular protein shown to be affected by nickel exposure. Mol. Reprod. Dev. 78:104–115, 2011. © 2010 Wiley‐Liss, Inc.