scholarly journals Limited proteolysis and site-directed mutagenesis reveal the origin of microheterogeneity in Rhodotorula gracilis D-amino acid oxidase

1998 ◽  
Vol 330 (2) ◽  
pp. 615-621 ◽  
Author(s):  
Stefano CAMPANER ◽  
Loredano POLLEGIONI ◽  
D. Brian ROSS ◽  
S. Mirella PILONE

When analysed by isoelectric focusing, D-amino acid oxidase from the yeast Rhodotorula gracilis normally consists of three molecular isoforms (pI 7.8, 7.4 and 7.2, respectively) all with the same N-terminal sequence. However, only a single band of pI 7.8 is detected with the recombinant wild-type protein expressed in E. coli. To determine whether the molecular basis of this heterogeneity is due to proteolysed forms of the protein, we treated R. gracilisd-amino acid oxidase with various proteases. Limited proteolysis by chymotrypsin and thermolysin produced truncated and nicked monomeric holoenzymes containing two polypeptides of ≈ 34 kDa (Met1-Leu312) and one of ≈ 5 kDa (Ala319-Arg364 with chymotrypsin or Ala319-Ala362 with thermolysin). On the other hand, treatment with endoproteinase Glu-C gave a dimeric holoenzyme lacking the C-terminal SKL tripeptide. This cleavage of Glu365-Ser366 peptide bond caused the disappearance of the three isoelectric bands and a single homogeneous band (pI 7.2) appeared. To study this protein form, we used site-directed mutagenesis to produce a mutant form of R. gracilisD-amino acid oxidase lacking the SKL C-terminal tripeptide (which is the targeting sequence PTS1 for peroxisomal proteins). As expected, the SKL-deleted mutant gave a single band (pI 7.2) in isoelectric focusing. The three-band pattern of native yeast enzyme was generated by in vitro experiments using an equimolar mixture of the wild-type (pI 7.8) and the SKL-deleted recombinant (pI 7.2) DAAOs. The microheterogeneity of yeast DAAO thus stems from the association of two polypeptide chains differing in the C-terminal tripeptide, giving three different holoenzyme dimers.

1999 ◽  
Vol 27 (1) ◽  
pp. A38-A38
Author(s):  
M.S. Pilone ◽  
G. Molla ◽  
C. Harris ◽  
D. Porrini ◽  
C. Vegezzi ◽  
...  

2010 ◽  
Vol 150 ◽  
pp. 442-442 ◽  
Author(s):  
N.V. Cherskova ◽  
S.V. Khoronenkova ◽  
M.A. Panteleev ◽  
V.I. Tishkov

2000 ◽  
Vol 27 (3-5) ◽  
pp. 234-239 ◽  
Author(s):  
Isabel de la Mata ◽  
Fernando Ramón ◽  
Virginia Obregón ◽  
Ma Pilar Castillón ◽  
Carmen Acebal

2019 ◽  
Vol 20 (18) ◽  
pp. 4412
Author(s):  
Denis L. Atroshenko ◽  
Mikhail D. Shelomov ◽  
Sophia A. Zarubina ◽  
Nikita Y. Negru ◽  
Igor V. Golubev ◽  
...  

d-amino acid oxidase (DAAO, EC 1.4.3.3) is used in many biotechnological processes. The main industrial application of DAAO is biocatalytic production of 7-aminocephalosporanic acid from cephalosporin C with a two enzymes system. DAAO from the yeast Trigonopsis variabilis (TvDAAO) shows the best catalytic parameters with cephalosporin C among all known DAAOs. We prepared and characterized multipoint TvDAAO mutants to improve their activity towards cephalosporin C and increase stability. All TvDAAO mutants showed better properties in comparison with the wild-type enzyme. The best mutant was TvDAAO with amino acid changes E32R/F33D/F54S/C108F/M156L/C298N. Compared to wild-type TvDAAO, the mutant enzyme exhibits a 4 times higher catalytic constant for cephalosporin C oxidation and 8- and 20-fold better stability against hydrogen peroxide inactivation and thermal denaturation, respectively. This makes this mutant promising for use in biotechnology. The paper also presents the comparison of TvDAAO catalytic properties with cephalosporin C reported by others.


2020 ◽  
Vol 168 (5) ◽  
pp. 557-567
Author(s):  
Wanitcha Rachadech ◽  
Yusuke Kato ◽  
Rabab M Abou El-Magd ◽  
Yuji Shishido ◽  
Soo Hyeon Kim ◽  
...  

Abstract Human D-amino acid oxidase (DAO) is a flavoenzyme that is implicated in neurodegenerative diseases. We investigated the impact of replacement of proline with leucine at Position 219 (P219L) in the active site lid of human DAO on the structural and enzymatic properties, because porcine DAO contains leucine at the corresponding position. The turnover numbers (kcat) of P219L were unchanged, but its Km values decreased compared with wild-type, leading to an increase in the catalytic efficiency (kcat/Km). Moreover, benzoate inhibits P219L with lower Ki value (0.7–0.9 µM) compared with wild-type (1.2–2.0 µM). Crystal structure of P219L in complex with flavin adenine dinucleotide (FAD) and benzoate at 2.25 Å resolution displayed conformational changes of the active site and lid. The distances between the H-bond-forming atoms of arginine 283 and benzoate and the relative position between the aromatic rings of tyrosine 224 and benzoate were changed in the P219L complex. Taken together, the P219L substitution leads to an increase in the catalytic efficiency and binding affinity for substrates/inhibitors due to these structural changes. Furthermore, an acetic acid was located near the adenine ring of FAD in the P219L complex. This study provides new insights into the structure–function relationship of human DAO.


1998 ◽  
Vol 330 (1) ◽  
pp. 311-314 ◽  
Author(s):  
F. RAMÓN ◽  
M. P. CASTILLÓN ◽  
I. DE LA MATA ◽  
C. ACEBAL

The variation of kinetic parameters of D-amino acid oxidase from Rhodotorula gracilis with pH was used to gain information about the chemical mechanism of the oxidation of D-amino acids catalysed by this flavoenzyme. D-Alanine was the substrate used. The pH dependence of Vmax and Vmax/Km for alanine as substrate showed that a group with a pK value of 6.26-7.95 (pK1) must be unprotonated and a group with a pK of 10.8-9.90 (pK2) must be protonated for activity. The lower pK value corresponded to a group on the enzyme involved in catalysis and whose protonation state was not important for binding. The higher pK value was assumed to be the amino group of the substrate. Profiles of pKi for D-aspartate as competitive inhibitor showed that binding is prevented when a group on the enzyme with a pK value of 8.4 becomes unprotonated; this basic group was not detected in Vmax/Km profiles suggesting its involvement in binding of the β-carboxylic group of the inhibitor.


2010 ◽  
Vol 33 (3) ◽  
pp. 557-563 ◽  
Author(s):  
Sandra Abad ◽  
Jozef Nahalka ◽  
Margit Winkler ◽  
Gabriele Bergler ◽  
Robert Speight ◽  
...  

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