scholarly journals Denaturation and renaturation of the monomeric phosphoglycerate mutase from Schizosaccharomyces pombe

1987 ◽  
Vol 245 (2) ◽  
pp. 525-530 ◽  
Author(s):  
C M Johnson ◽  
N C Price

The denaturation by guanidinium chloride of the monomeric phosphoglycerate mutase from Schizosaccharomyces pombe was studied. The loss in activity broadly parallels the changes in protein structure detected by fluorescence and c.d. Renaturation can be brought about by dilution of the denaturing agent. These processes were compared with those in the enzymes from baker's yeast and rabbit muscle, which are tetrameric and dimeric respectively. The effects of the cofactor 2,3-bisphosphoglycerate on the structure and stability of the S. pombe enzyme were also investigated.

1986 ◽  
Vol 236 (2) ◽  
pp. 617-620 ◽  
Author(s):  
C M Johnson ◽  
N C Price

The renaturation of the tetrameric enzyme phosphoglycerate mutase from baker's yeast after denaturation in guanidinium chloride was studied. Three proteinases (trypsin, chymotrypsin and thermolysin) cause extensive loss of activity of samples taken during the early stages of refolding. As judged by SDS/polyacrylamide-gel electrophoresis, the proteinases cause substantial degradation of the polypeptide chain with no evidence for large quantities of fragments of Mr greater than 6500. These data suggest that the early intermediates in the refolding, especially the folded monomer, possess a number of sites that are susceptible to proteolysis.


1988 ◽  
Vol 251 (1) ◽  
pp. 135-139 ◽  
Author(s):  
S M West ◽  
N C Price

The unfolding behaviour of the hexameric glutamate dehydrogenases from bovine liver, Clostridium symbosium and baker's yeast in solutions of guanidinium chloride (GdnHCl) was studied. Changes in Mr studied by light-scattering indicate that, in each case, the hexamer dissociates to form trimers, which then dissociate to monomers at higher concentrations of GdnHCl. Dissociation to trimers is accompanied by a reversible loss of enzyme activity, but no gross structural changes can be detected by fluorescence or c.d. Dissociation to monomers is accompanied by large structural changes, and the loss of activity cannot be reversed by dilution. The parallel behaviour of all three enzymes shows that the previously noted inability of the isolated subunits of the bovine liver enzyme to refold [Bell & Bell (1984) Biochem. J. 217, 327-330] is not a result of any modification of the enzyme as a result of import into mitochondria, since the C. symbosium and baker's-yeast enzymes do not undergo any such post-translational translocation.


1974 ◽  
Vol 52 (1) ◽  
pp. 51-59 ◽  
Author(s):  
Roderick A. McDonald ◽  
T. Satyanarayana ◽  
J. G. Kaplan

The activities and regulation of the enzymes of the synthetic pathway of branched-chain amino acids were investigated in the fission yeast, Schizosaccharomyces pombe. Previous studies had shown the presence of threonine deaminase (TD) and acetohydroxy acid synthetase (AHAS). The remaining isoleucine–valine enzymes, isomeroreductase (IR), dehydrase, and transaminase B, have now been characterized in cell-free extracts, indicating the presence in this yeast of the complete pathway as demonstrated in other microorganisms. α-Isopropylmalate synthetase (IPMS), the first enzyme of the leucine pathway, has properties of a typical regulatory enzyme; it is most active in the pH range 7.5–8.5, but is most sensitive to feedback inhibition by L-leucine at pH 6.5–7.0. Unlike the situation in baker's yeast, only AHAS and IR appeared to be subject to multivalent repression. TD was relatively resistant to any change in level, and AHAS was repressible by valine included in the growth medium. IPMS was repressed when cells were grown in complex medium; leucine alone did not cause repression, and in contrast with baker's yeast, neither did leucine plus threonine or a combination of all three branched-chain amino acids.


2009 ◽  
Vol 75 (9) ◽  
pp. 2765-2774 ◽  
Author(s):  
Esben H. Hansen ◽  
Birger Lindberg Møller ◽  
Gertrud R. Kock ◽  
Camilla M. Bünner ◽  
Charlotte Kristensen ◽  
...  

ABSTRACT Vanillin is one of the world's most important flavor compounds, with a global market of 180 million dollars. Natural vanillin is derived from the cured seed pods of the vanilla orchid (Vanilla planifolia), but most of the world's vanillin is synthesized from petrochemicals or wood pulp lignins. We have established a true de novo biosynthetic pathway for vanillin production from glucose in Schizosaccharomyces pombe, also known as fission yeast or African beer yeast, as well as in baker's yeast, Saccharomyces cerevisiae. Productivities were 65 and 45 mg/liter, after introduction of three and four heterologous genes, respectively. The engineered pathways involve incorporation of 3-dehydroshikimate dehydratase from the dung mold Podospora pauciseta, an aromatic carboxylic acid reductase (ACAR) from a bacterium of the Nocardia genus, and an O-methyltransferase from Homo sapiens. In S. cerevisiae, the ACAR enzyme required activation by phosphopantetheinylation, and this was achieved by coexpression of a Corynebacterium glutamicum phosphopantetheinyl transferase. Prevention of reduction of vanillin to vanillyl alcohol was achieved by knockout of the host alcohol dehydrogenase ADH6. In S. pombe, the biosynthesis was further improved by introduction of an Arabidopsis thaliana family 1 UDP-glycosyltransferase, converting vanillin into vanillin β-d-glucoside, which is not toxic to the yeast cells and thus may be accumulated in larger amounts. These de novo pathways represent the first examples of one-cell microbial generation of these valuable compounds from glucose. S. pombe yeast has not previously been metabolically engineered to produce any valuable, industrially scalable, white biotech commodity.


1994 ◽  
Vol 299 (2) ◽  
pp. 347-350 ◽  
Author(s):  
T I Koshy ◽  
T L Luntz ◽  
B Plotkin ◽  
A Schejter ◽  
E Margoliash

The residue asparagine-52 of rat cytochrome c and baker's yeast iso-1-cytochrome c was mutated to isoleucine by site-directed mutagenesis, and the unfolding of the wild-type and mutant proteins in urea or guanidinium chloride solutions was studied. Whereas the yeast mutant cytochrome unfolded in 4-7 M urea with a rate constant (k) of 1.7 x 10(-2) s-1, the rat mutant protein unfolded with k = 5.0 x 10(-2) s-1, followed by a slow partial refolding with k = 5.0 x 10(-4) s-1. Denaturant titrations indicated that the mutation increased the stability of the yeast cytochrome by 6.3 kJ (1.5 kcal)/mol, while it decreased that of the rat protein by 11.7 kJ (2.8 kcal)/mol. These results probably reflect structural differences between yeast iso-1 and vertebrate cytochromes c in the vicinity of the Asn-52 side chain.


2014 ◽  
Vol 13 (12) ◽  
pp. 3153-3160 ◽  
Author(s):  
Zakaria Al-Qodah ◽  
Mohammad Al-Shannag ◽  
Kholoud Alananbeh ◽  
Nahla Bouqellah ◽  
Eman Assirey ◽  
...  

Author(s):  
Ida N Jamal ◽  
Reiny A Tumbol ◽  
Remy E.P Mangindaan

Motile Aeromonas Septicaemia disease (MAS) attacking tilapia has increased in recent years as a consequence of intensive aquaculture activities, which led to losses in aquaculture industry. The agent causing MAS disease is Aeromonas hydrophila. The disease can be controlled with the β-glucan. As immunostimulants, β-glucans can also increase resistance in farmed tilapia. Studies on the use of β-glucan extracted from baker's yeast Saccharomyces cerevisiae was intended to evaluate the non-specific immune system of tilapia that were challenged with Aeromonas hydrophila. The method used was an experimental method with a completely randomized design consisting of four treatments with three replicats. The dose of β-glucan used as treatments were 0 mg.kg-1 fish (Control), 5 mg.kg-1 fish (B), 10 mg.kg-1 fish (C) and 20 mg.kg-1 fish (D), each treatment as injected three times at intervals of 3 days, the injection volume of 0.5 ml/fish for nine days and resistance surveillance for seven days. The results showed that the difference in the amount of β-glucan and the frequency of the injected real influence on total leukocytes, phagocytic activity and resistance. Total leukocytes, phagocytic activity and resistance to treatment was best achieved by the administration of C a dose of  10 mg.kg-1 of the fish© Penyakit Motil Aeromonas Septicaemia (MAS) yang menyerang ikan nila mengalami peningkatan selama beberapa tahun terakhir sebagai konsekuensi dari kegiatan akuakultur intensif, yang menyebabkan kerugian dalam industri budidaya. Agen utama penyebab penyakit MAS adalah Aeromonas hydrophila. Untuk mengendalikan penyakit tersebut dapat dilakukan dengan pemberian β-glukan. Sebagai imunostimulan, β-glukan juga dapat  meningkatkan resistensi pada ikan nila yang dibudidayakan. Pengkajian mengenai pemanfaatan β-glukan yang diekstrak dari ragi roti Saccharomyces cerevisiae dimaksudkan untuk menguji sistem imun non spesifik ikan nila yang diuji tantang dengan bakteri Aeromonas hydrophila. Metode yang digunakan yaitu metode eksperimen dengan rancangan acak lengkap yang terdiri dari empat perlakuan dan tiga ulangan. Dosis β-glukan  yang digunakan sebagai perlakuan sebesar 0 mg.kg-1 ikan (Kontrol), 5 mg.kg-1 ikan (B), 10 mg.kg-1 ikan (C) dan 20 mg.kg-1 ikan (D), masing-masing perlakuan diinjeksi sebanyak 3 kali dengan interval waktu 3 hari selama 9 hari, volume injeksi 0,5 mL/ekor ikan dan pengamatan resistensi selama tujuh hari. Hasil penelitian menunjukkan perbedaan jumlah β-glukan dan frekuensi pemberian yang diinjeksikan memberikan pengaruh nyata terhadap total leukosit, aktivitas fagositosis dan resistensi. Total leukosit, aktivitas fagositosis dan resistensi terbaik dicapai pada perlakuan C dengan dosis 10 mg.kg-1 ikan©


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