• Türkçe
    • English
  • Türkçe 
    • Türkçe
    • English
  • Giriş
Öğe Göster 
  •   Açık Erişim Ana Sayfası
  • Avesis
  • Dokümanı Olmayanlar
  • Makale
  • Öğe Göster
  •   Açık Erişim Ana Sayfası
  • Avesis
  • Dokümanı Olmayanlar
  • Makale
  • Öğe Göster
JavaScript is disabled for your browser. Some features of this site may not work without it.

SOME PROPERTIES OF GLUTAMATE-DEHYDROGENASE, GLUTAMINE-SYNTHETASE AND GLUTAMATE SYNTHASE FROM CORYNEBACTERIUM-CALLUNAE

Tarih
1992
Yazar
ERTAN, H
Üst veri
Tüm öğe kaydını göster
Özet
Characteristics of the three major ammonia assimilatory enzymes, glutamate dehydrogenase (GDH), glutamine synthetase (GS) and glutamate synthase (GOGAT) in Corynebacterium callunae (NCIB 10338) were examined. The GDH of C. callunae specifically required NADPH and NADP+ as coenzymes in the amination and deamination reactions, respectively. This enzyme showed a marked specificity for alpha-ketoglutarate and glutamate as substrates. The optimum pH was 7.2 for NADPH-GDH activity (amination) and 9.0 for NADP+-GDH activity (deamination). The results showed that NADPH-GDH and NADP+-GDH activities were controlled primarily by product inhibition and that the feedback effectors alanine and valine played a minor role in the control of NADPH-GDH activity. The transferase activity of GS was dependent on Mn+2 while the biosynthetic activity of the enzyme was dependent on Mg2+ as essential activators. The pH optima for transferase and biosynthetic activities were 8.0 and 7.0, respectively. In the transfer reaction, the K(m) values were 15.2 mM for glutamine, 1.46 mM for hydroxylamine, 3.5 x 10(-3) mM for ADP and 1.03 mM for arsenate. Feedback inhibition by alanine, glycine and serine was also found to play an important role in controlling GS activity. In addition, the enzyme activity was sensitive to ATP. The transferase activity of the enzyme was responsive to ionic strength as well as the specific monovalent cation present. GOGAT of C. callunae utilized either NADPH or NADH as coenzymes, although the latter was less effective. The enzyme specifically required alpha-ketoglutarate and glutamine as substrates. In cells grown in a medium with glutamate as the nitrogen source, the optimum pH was 7.6 for NADPH-GOGAT activity and 6.8 for NADH-GOGAT activity. Findings showed that NADPH-GOGAT and NADH-GOGAT activities were controlled by product inhibition caused by NADP+ and NAD+, respectively, and that ATP also had an important role in the control of NADPH-GOGAT activity. Both activities of GOGAT were found to be inhibited by azaserine.
Bağlantı
http://hdl.handle.net/20.500.12627/133159
https://doi.org/10.1007/bf00249063
Koleksiyonlar
  • Makale [92796]

Creative Commons Lisansı

İstanbul Üniversitesi Akademik Arşiv Sistemi (ilgili içerikte aksi belirtilmediği sürece) Creative Commons Alıntı-GayriTicari-Türetilemez 4.0 Uluslararası Lisansı ile lisanslanmıştır.

DSpace software copyright © 2002-2016  DuraSpace
İletişim | Geri Bildirim
Theme by 
Atmire NV
 

 


Hakkımızda
Açık Erişim PolitikasıVeri Giriş Rehberleriİletişim
sherpa/romeo
Dergi Adı/ISSN || Yayıncı

Exact phrase only All keywords Any

BaşlıkbaşlayaniçerenISSN

Göz at

Tüm DSpaceBölümler & KoleksiyonlarTarihe GöreYazara GöreBaşlığa GöreKonuya GöreTürlere GöreBu KoleksiyonTarihe GöreYazara GöreBaşlığa GöreKonuya GöreTürlere Göre

Hesabım

GirişKayıt

Creative Commons Lisansı

İstanbul Üniversitesi Akademik Arşiv Sistemi (ilgili içerikte aksi belirtilmediği sürece) Creative Commons Alıntı-GayriTicari-Türetilemez 4.0 Uluslararası Lisansı ile lisanslanmıştır.

DSpace software copyright © 2002-2016  DuraSpace
İletişim | Geri Bildirim
Theme by 
Atmire NV