Wyniki wyszukiwania - Biblioteka Nauki

1

Regulation of bacterial protease activity

100%

Wladyka B. , Pustelny K.

|

tom 13

|

nr 2

212-229

EN

Proteases, also referred to as peptidases, are the enzymes that catalyse the hydrolysis of peptide bonds in polipeptides. A variety of biological functions and processes depend on their activity. Regardless of the organism’s complexity, peptidases are essential at every stage of life of every individual cell, since all protein molecules produced must be proteolytically processed and eventually recycled. Protease inhibitors play a crucial role in the required strict and multilevel control of the activity of proteases involved in processes conditioning both the physiological and pathophysiological functioning of an organism, as well as in host-pathogen interactions. This review describes the regulation of activity of bacterial proteases produced by dangerous human pathogens, focusing on the Staphylococcus genus.

2

Proteomics in studies of Staphylococcus aureus virulence

80%

Bonar E. , Wojcik I. , Wladyka B.

Acta Biochimica Polonica

|

2015

|

tom 62

|

nr 3

3

Prokaryotic toxin-antitoxin systems - the role in bacterial physiology and application in molecular biology

80%

Bukowski M. , Rojowska A. , Wladyka B.

Acta Biochimica Polonica

|

2011

|

tom 58

|

nr 1

EN

Bacteria have developed multiple complex mechanisms ensuring an adequate response to environmental changes. In this context, bacterial cell division and growth are subject to strict control to ensure metabolic balance and cell survival. A plethora of studies cast light on toxin-antitoxin (TA) systems as metabolism regulators acting in response to environmental stress conditions. Many of those studies suggest direct relations between the TA systems and the pathogenic potential or antibiotic resistance of relevant bacteria. Other studies point out that TA systems play a significant role in ensuring stability of mobile genetic material. The evolutionary origin and relations between various TA systems are still a subject of a debate. The impact of toxin-antitoxin systems on bacteria physiology prompted their application in molecular biology as tools allowing cloning of some hard-to-maintain genes, plasmid maintenance and production of recombinant proteins.

4

Evaluation of P1' substrate specificity of staphylococcal SplB protease

70%

Pustelny K. , Stach N. , Wladyka B. , Dubin A. , Dubin G.

Acta Biochimica Polonica

|

2014

|

tom 61

|

nr 1

EN

Staphylococcus aureus is a dangerous human pathogen characterized by growing antibiotic resistance. Virulence of S. aureus relies on a variety of secreted and cell surface associated virulence factors among which certain proteolytic enzymes play an important role. Amid staphylococcal extracellular proteases, those encoded by the spl operon remain poorly characterized, both in terms of enzymology and their physiological role. Initial data demonstrated that Spl proteases exhibit restricted substrate specificity. This study describes development of convenient protein FRET substrates for SplB protease and characterization of the substrate preference of the protease at the P1' position. Kinetic data on hydrolysis of a panel of substrates substituted at the said position is provided.

5

Drug resistance spread by horizontal gene transfer exemlified by plasmids derived from Staphylococcus aureus strains of animal origin

70%

Bukowski M. , Piwowarczyk R. , Zagorski-Przybylo R. , Hydzik M. , Wladyka B.

Postępy Mikrobiologii. Suplement

|

2017

|

tom 56

|

nr 3

6

The first case of a Staphylococcus pseudintermedius infection after joint prosthesis implantation in a dog

61%

Miedzobrodzki J. , Kasprowicz A. , Bialecka A. , Jaworska O. , Polakowska K. , Wladyka B. , Dubin A.

Polish Journal of Microbiology

|

2010

|

tom 59

|

nr 2

133-135

EN

We have reported a bacterial infection in a dog with progressive dysplasia of the hips. Orthopedic surgery was performed. Seven weeks prior to the surgery, the patient was bitten by another dog. The postimplantation wound exuded for four days after the surgery. Microbiological analysis performed by standard identification techniques showed the presence of Staphylococcus intermedins, but an additional molecular analysis indicated S. pseudintermedius. This was followed by an evaluation of antibiotic susceptibility of the strain which showed cefoxitin, ciprofloxacin, clindamycin, trimethoprim/sulfamethoxazole, doksycycline, erythromycin, and gentamicin resistance. Minimal inhibitory concentration (MIC) values for selected antibiotics were reported. Resistance for cefoxitin indicates that methicillin resistant S. pseudintermedius (MRSP) strains were present in individual macroorganisms, but they can expand and persist the colonization of other hosts.

7

A novel member of the thermolysin family, cloning and biochemical characterization of metalloprotease from Staphylococcus pseudintermedius

61%

Wladyka B. , Bista M. , Sabat A. J. , Bonar E. , Grzeszczuk S. , Hryniewicz W. , Dubin A.

Acta Biochimica Polonica

|

2008

|

tom 55

|

nr 3

525-536

EN

Thermolysins constitute a family of secreted bacterial metalloproteases expressed, among others, by several pathogens. Strains of Staphylococcus pseudintermedius isolated from diseased dogs and judged as protease-positive, by skim milk agar plate culture, were investigated for protease content. No proteolytic activity was detected when the bacteria were grown in regular liquid media. Unexpectedly, supplementation of the medium with calcium ions resulted in expression of a metalloprotease and profound changes in the profile of extracellular proteins. On the basis of homology to other staphylococcal metalloproteases, the nucleotide sequence of the gene encoding this protease (Pst) and its flanking regions was determined. The full-length pstcodes for a protein with an open reading frame of 505 amino acids. The internal region contains the HEXXH catalytic domain that is conserved in members of the thermolysin family. Regardless of the presence of calcium in the medium, the expression of the protease gene was of the same intensity. This suggests that regulation of the metalloprotease production by calcium ions is at a post-transcriptional level. Isolates of S. pseudintermediusexhibit a proteolytic phenotype due to the metalloprotease expression, however only in presence of calcium ions, which most probably stabilize the structure of the protease.

8

A systematic investigation of the stability of green fluorescent protein fusion proteins

61%

Janczak M. , Bukowski M. , Gorecki A. , Dubin G. , Dubin A. , Wladyka B.

Acta Biochimica Polonica

|

2015

|

tom 62

|

nr 3

9

New generation of peptide antibiotics

51%

Dubin A. , Mak P. , Dubin G. , Rzychon M. , Stec-Niemczyk J. , Wladyka B. , Maziarka K. , Chmiel D.

Acta Biochimica Polonica

|

2005

|

tom 52

|

nr 3

EN

The increasing antibiotic resistance of pathogenic bacteria calls for the development of alternative antimicrobial strategies. Possible approaches include the development of novel, broad-spectrum antibiotics as well as specific targeting of individual bacterial virulence factors. It is impossible to decide currently which strategy will prove more successful in the future since they both promise different advantages, but also introduce diverse problems. Considering both approaches, our laboratory's research focuses on the evaluation of hemocidins, broad-spectrum antibacterial peptides derived from hemoglobin and myoglobin, and staphostatins, specific inhibitors of staphopains - Staphylococcus aureus secreted proteases that are virulence factors regarded as possible targets for therapy. The article summarizes recent advances in both fields of study and presents perspectives for further development and possible applications.

10

The role of Staphylococcus aureus saoABC operon in stress response, intracellular survival and persister formation

41%

Madry A. , Kosecka-Strojek M. , Buda A. , Gawron K. , Bonar E. , Lazarz-Bartyzel K. , Chomyszyn-Gajewska M. , Wladyka B. , Potempa J. , Miedzobrodzki J. , Bukowski M.

Postępy Mikrobiologii. Suplement

|

2017

|

tom 56

|

nr 3