Studies on secreted cysteine proteases of Streptococcus pyogenes : IdeS and SpeB

The pathogen Streptococcus pyogenes is a significant cause of human morbidity and mortality. Most of the work in this thesis is focused on streptococcal virulence factor IdeS, but the thesis also features work on SpeB, another streptococcal virulence factor. Both IdeS and SpeB are secreted cysteine proteases and both have previously been shown to degrade human IgG. IgG is the only known substrate for IdeS while SpeB is a more promiscuous protease with a larger number of identified substrates. A significant part of the data presented in this thesis is the result of designing and optimizing methods to detect and accurately measure the proteolytic degradation of IgG. Methods aimed at measuring the binding interactions between enzyme and substrate have also been frequently utilized. I show that IdeS is a monomeric protease, as opposed to previously published data that suggested it to be dimeric. IdeS cleaves the two heavy chains of IgG in a two-step reaction and I demonstrate that the first cleavage is magnitudes faster than the second one. This means that IdeS is a more efficient enzyme than previously thought. The difference in rate cannot completely be explained by a loss of affinity between IdeS and IgG after the cleavage of the first heavy chain. The velocity of IdeS is further increased by the presence of human Cystatin C, via an unknown mechanism. Cystatin C is normally a protease inhibitor and it having an opposite effect is puzzling.The synthesis and evaluation of novel inhibitors are also described. Peptide analogues mimicking the sequence surrounding the scissile bond on IgG - with an amino acid replaced with a more rigid motif - act as specific, but low-affinity, inhibitors of IdeS. The peptide analogues’ inhibitory capacity for SpeB and papain was also assayed.When it comes to SpeB, I show that it does not have IgG as a substrate under physiological conditions, in contrast to what was previously thought. This thesis does not only present findings on the IgG degrading capacity of IdeS and SpeB but also include data on fundamental enzymatic properties for these proteases

Ekonomistyrning i redovisnings-, lönekonsult och revisionsbyråer Hur kan ekonomistyrning se ut i små redovisnings-, lönekonsult och revisionsbyråer?

Sammanfattning Examensarbetets titel: Hur kan ekonomistyrning se ut i små redovisnings-, lönekonsult och revisionsbyråer Seminariedatum: 13 januari 2017 Kurs: FEKH69, Examensarbete i redovisning på kandidatnivå, 15 högskolepoäng Författare: Reine Vindebro, Michael Wendwessen och Caroline Åkesson Handledare: Peter W Jönsson Fem nyckelord: Företagsekonomi, ekonomistyrning, MCS, professionella tjänsteföretag, små företag Syfte: Syftet med uppsatsen är att beskriva hur ekonomistyrningen ser ut i små redovisnings-, lönekonsult och revisionsbyråer Metod: Studien bygger på en kvalitativ forskningsstrategi med semi-strukturerade intervjuer. Ambitionen är att ha en induktiv forskningsansats men innehåller trots det deduktiva inslag. Teoretiska perspektiv: Studiens teoretiska referensram tar stöd från forskningsartiklar och kurslitteratur. Empiri: Studiens empiri baseras på fyra intervjuer. Intervjuerna genomfördes på plats i byråerna. Resultat: Vi kan i vår studie fastställa att användningen av ekonomistyrning varierar i de små redovisnings-, lönekonsult och revisionsbyråer som vi har undersökt. Gemensamt för alla företagen är de använder sig av både formell- och mindre formell styrning, samt resultat- och handlingsstyrning.Abstract Title: How do small accounting-, payroll consultant and auditing agencies use management control in their businesses. Seminar date: 13th of January 2017 Course: FEKH69, Degree Project Bachelor level, Business Administration, 15 ECTS Credits Authors: Reine Vindebro, Michael Wendwessen and Caroline Åkesson Advisor: Peter W Jönsson Key words: Business administration, management control, MCS, professional services business, small companies. Purpose: The purpose with this essay is to describe the use of management control in small accounting-, payroll consultant and auditing agencies. Methodology: The study is based on a qualitative academic strategy with semi-structured interviews. Our ambition is to have an inductive academic approach that have deductive approach as well to a certain extent. Theoretical perspectives: The theoretical perspectives of the study take support from academic journals and course literature. Empirical foundation: The empirical foundation is based on four interviews. The interviews were performed at the agencies. Conclusions: We have come to the conclusion that the use of management control vary in the small accounting-, payroll consultant and auditing agencies that we examined. Common to all businesses is the use of both formal and informal control, as well as result and actioncontrol

The Human Protease Inhibitor Cystatin C Is an Activating Cofactor for the Streptococcal Cysteine Protease IdeS

SummaryHuman cystatin C is considered the physiologically most important inhibitor of endogenous papain-like cysteine proteases. We present here an unexpected function of cystatin C. Instead of acting as an inhibitor, cystatin C acts as a facultative, endogenous cofactor for the papain-like IgG-cleaving enzyme IdeS of the human pathogen Streptococcus pyogenes. IdeS activity is not dependent on cystatin C, but is significantly enhanced in the presence of cystatin C. We report a protease inhibitor that accelerates the activity of its putative target protease and a unique example of how a host protease inhibitor is “hijacked” by a bacterial protease to increase its activity. This finding has important implications for the view on protease-inhibitor interactions, and is relevant to consider in the therapeutic use of protease inhibitors

3-Aminopiperidine-Based Peptide Analogues as the First Selective Noncovalent Inhibitors of the Bacterial Cysteine Protease IdeS

A series of eight peptides corresponding to the amino acid sequence of the hinge region of IgG and 17 newly synthesized peptide analogues containing a piperidine moiety as a replacement of a glycine residue were tested as potential inhibitors of the bacterial IgG degrading enzyme of Streptococcus pyogenes, IdeS. None of the peptides showed any inhibitory activity of IdeS, but several piperidine-based analogues were identified as inhibitors. Two different analysis methods were used: an SDS-PAGE based assay to detect IgG cleavage products and a surface plasmon resonance spectroscopy based assay to quantify the degree of inhibition. To investigate the selectivity of the inhibitors for IdeS, all compounds were screened against two other related cysteine proteases (SpeB and papain). The selectivity results show that larger analogues that are active inhibitors of IdeS are even more potent as inhibitors of papain, whereas smaller analogues that are active inhibitors of IdeS inhibit neither SpeB nor papain. Two compounds were identified that exhibit high selectivity against IdeS and will be used for further studies