Enhancing activity and thermostability of lipase A from Serratia marcescens by site-directed mutagenesis

2016 ◽  
Vol 93-94 ◽  
pp. 18-28 ◽  
Author(s):  
Mohsen Mohammadi ◽  
Zargham Sepehrizadeh ◽  
Azadeh Ebrahim-Habibi ◽  
Ahmad Reza Shahverdi ◽  
Mohammad Ali Faramarzi ◽  
...  
Keyword(s):  
Serratia Marcescens ◽  
Site Directed Mutagenesis ◽  
Directed Mutagenesis ◽  
Lipase A

Prediction of the Candida antarctica Lipase A Protein Structure by Comparative Modeling and Site-Directed Mutagenesis.

ChemInform ◽  
2007 ◽  
Vol 38 (44) ◽  
Author(s):  
Alex Kasrayan ◽  
Marco Bocola ◽  
Anders G. Sandstroem ◽  
Gaston Laven ◽  
Jan-E. Baeckvall
Keyword(s):  
Protein Structure ◽  
Comparative Modeling ◽  
Candida Antarctica ◽  
Site Directed Mutagenesis ◽  
Directed Mutagenesis ◽  
Candida Antarctica Lipase ◽  
Lipase A

Site-directed mutagenesis studies to probe the role of specific residues in the external loop (L3) of OmpF and OmpC porins in susceptibility of Serratia marcescens to antibiotics

2007 ◽  
Vol 53 (6) ◽  
pp. 710-719
Author(s):  
Sanela Begic ◽  
Elizabeth A. Worobec
Keyword(s):  
Amino Acid ◽  
Serratia Marcescens ◽  
Outer Membrane ◽  
Aspartic Acid ◽  
Site Directed Mutagenesis ◽  
Natural Resistance ◽  
Directed Mutagenesis ◽  
External Loop ◽  
Ompc Porin

Serratia marcescens is a nosocomial bacterium with natural resistance to a broad spectrum of antibiotics, making treatment challenging. One factor contributing to this natural antibiotic resistance is reduced outer membrane permeability, controlled in part by OmpF and OmpC porin proteins. To investigate the direct role of these porins in the diffusion of antibiotics across the outer membrane, we have created an ompF–ompC porin-deficient strain of S. marcescens. A considerable similarity between the S. marcescens porins and those from other members of Enterobacteriaceae was detected by sequence alignment, with the exception of a change in a conserved region of the third external loop (L3) of the S. marcescens OmpC protein. Serratia marcescens OmpC has aspartic acid instead of glycine in position 112, methionine instead of aspartic acid in position 114, and glutamine in position 124, while in S. marcescens OmpF this is a glycine at position 124. To investigate the role of amino acid positions 112, 114, and 124 and how the observed changes within OmpC porin may play a part in pore permeability, 2 OmpC sites were altered in the Enterobacteriaceae consensus (D112G and M114D) through site-directed mutagenesis. Also, Q124G in OmpC, G124Q in OmpF, and double mutants of these amino acid residues were constructed. Antibiotic accumulation assays and minimal inhibitory concentrations of the strains harboring the mutated porins were performed, while liposome swelling experiments were performed on purified porins. Our results demonstrate that the amino acid at position 114 is not responsible for either antibiotic size or ionic selection, the amino acid at position 112 is responsible for size selection only, and position 124 is involved in both size and ionic selection.

scholarly journals Sequences of Homologous β-Lactamases from Clinical Isolates of Serratia marcescens with Different Substrate Specificities

1998 ◽  
Vol 42 (1) ◽  
pp. 176-179 ◽  
Author(s):  
Naoki Matsumura ◽  
Shinzaburo Minami ◽  
Susumu Mitsuhashi
Keyword(s):  
Serratia Marcescens ◽  
Site Directed Mutagenesis ◽  
Clinical Isolates ◽  
Directed Mutagenesis ◽  
Substrate Specificities ◽  
The Third ◽  
Group 1

ABSTRACT Genes for two group 1 β-lactamases, SRT-1 and SST-1, were sequenced. These β-lactamases were produced by clinical isolates ofSerratia marcescens, isolates GN16694 and GN19450, respectively. The resulting enzymes were 96% identical. SRT-1 hydrolyzed oxyimino cephalosporins, but SST-1 hardly hydrolyzed them. At residue 213 in the third motif, which is conserved among group 1 β-lactamases, SRT-1 and SST-1 had Lys and Glu, respectively. By site-directed mutagenesis, the substitution of Glu by Lys at residue 213 in SST-1 resulted in an enzyme that hydrolyzed oxyimino cephalosporins.

Improving the thermostability of Serratia marcescens B4A chitinase via G191V site-directed mutagenesis

2018 ◽  
Vol 116 ◽  
pp. 64-70 ◽  
Author(s):  
Zeinab Emruzi ◽  
Saeed Aminzadeh ◽  
Ali Asghar Karkhane ◽  
Jahan Alikhajeh ◽  
Kamahldin Haghbeen ◽  
...  
Keyword(s):  
Serratia Marcescens ◽  
Site Directed Mutagenesis ◽  
Directed Mutagenesis

Prediction of theCandida antarctica Lipase A Protein Structure by Comparative Modeling and Site-Directed Mutagenesis

ChemBioChem ◽  
2007 ◽  
Vol 8 (12) ◽  
pp. 1409-1415 ◽  
Author(s):  
Alex Kasrayan ◽  
Marco Bocola ◽  
Anders G. Sandström ◽  
Gaston Lavén ◽  
Jan-E. Bäckvall
Keyword(s):  
Protein Structure ◽  
Comparative Modeling ◽  
Site Directed Mutagenesis ◽  
Directed Mutagenesis ◽  
Lipase A
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