Effects of microwave treated substrate on pepsin reaction kinetics

Microwave (MW) irradiated bovine serum albumin (BSA) and bromphenol blue (BPB) complex was used as substrate for the assay of pepsin by kinetic method. Decreased reaction velocity under absorbed MW energy and constant temperature was observed.Physical chemistry 2008 : 9th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 24-28 September 200

Temperature and Al3+ influence on electrophoretic mobility of porcine pepsin

The influence of temperature and different concentrations of Al3+ on pepsin electrophoretic mobility was investigated. The increase of Al3+ concentrations causes the decrease the electrophoretic mobility of enzyme. Also the increase of temperature induced the same effect. The influence of both temperature and Al3+ ion concentrations is additive.Physical chemistry 2006 : 8th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 26-29 September 200

Non-essential activation of pepsin by Al3+ “in vitro”

The in vitro effect of Al3+ ions on pepsin activity at pH 2, via kinetic parameters was evaluated. Kinetic study showed that Al3+ ions increase the maximal velocity (Vmax) rather than apparent affinity for substrate (KS) implying the non-competitive nature of activation which indicated that aluminium was a non-essential activator of partial non-competitive type.Physical chemistry 2008 : 9th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 24-28 September 200

Dejstvo rifamicina i hloramfenikola na produkciju antibiotika i proteaza soja Streptomyces hygroscopicus CH-7

Streptomycetes are common soil bacteria that grow in a filamentous form and produced spores. Secondary metabolites, particularly antibiotics, as well as extracellular enzymes produced by them have very significant role in the process of differentiation. The Slreptomyces hygroscopicus CH-7 strain produces polyketide antibiotics and an extracellular proteolytic complex. The aim of this work was to establish the influence of transcription and translation inhibitors on biosynthesis of polyene antibiotic and proteolytic enzymes. The inhibitors were added at inoculation and at specific time intervals of fermentation. The production of hexaene H-85 is susceptible to rifamycin (transcription inhibitor) and chloramphenicol (translation inhibitor). Rifamycin reduces the production and trypsin like protease (TLP) and aminopeptidase (AP). while chloramphenicol acts only on TLP. Simultaneously these inhibitors almost have no effect on strain growth.Streptomicete su gram pozitivne bakterije čije je najvažnije stanište zemlja. Pri rastu na čvrstim podlogama i u submerznim uslovima grade supstratni i vazdušni micelijum. Morfološka diferencijacija je praćena produkcijom sekundarnih metabolita kao što su antibiotici, a i različitih hidrolitičkih enzima. Za mikroorganizme koji ih proizvode antibiotici predstavljaju kompetitivno oružje, agense za transport metala kao i efektore diferencijacije. Proteolitički enzimi, takođe, imaju određenu ulogu u razvojnom ciklusu aktinomiceta. Na primer, uključeni su u procese građenja vazdušnog micelija i sporulaciju. Soj Streptomyces hygroscopicus CH-7 pri fermentaciji proizvodi antibiotike poliketidne strukture i smesu ekstracelularnih proteolitičkih enzima. U ovom radu je ispitivan uticaj antibiotika rifamicina i hloramfenikola, inhibitora transkripcije i translacije, na produkciju polienskog antibiotika heksaena H-85 i proteolitičkih enzima. Inhibited su dodavani pri inokulaciji (O h) i u različitim vremenskim intervalima fermentacije (12-48 h). Dejstvom antibiotika inhibitora transkripcije i translacije utvrdjeno je da se enzim polien sintetaza transkribuje do 12. časa, a translacija teče do 48. časa fermentacije. Dodatak rifamicina pri zasejavanju drastično snižava proteolitičku aktivnost, a u kasnijim fazama izaziva smanjenje (36-80%). Hloramfenikol smanjuje produkciju tripsinu slične proteaze. ali nema dejstvo na aminopeptidaznu aktivnost. Rifamicin i hloramfenikol ne pokazuju značajno inhibitorno dejstvo na rast soja

Dejstvo rifamicina i hloramfenikola na produkciju antibiotika i proteaza soja Streptomyces hygroscopicus CH-7

Streptomycetes are common soil bacteria that grow in a filamentous form and produced spores. Secondary metabolites, particularly antibiotics, as well as extracellular enzymes produced by them have very significant role in the process of differentiation. The Slreptomyces hygroscopicus CH-7 strain produces polyketide antibiotics and an extracellular proteolytic complex. The aim of this work was to establish the influence of transcription and translation inhibitors on biosynthesis of polyene antibiotic and proteolytic enzymes. The inhibitors were added at inoculation and at specific time intervals of fermentation. The production of hexaene H-85 is susceptible to rifamycin (transcription inhibitor) and chloramphenicol (translation inhibitor). Rifamycin reduces the production and trypsin like protease (TLP) and aminopeptidase (AP). while chloramphenicol acts only on TLP. Simultaneously these inhibitors almost have no effect on strain growth.Streptomicete su gram pozitivne bakterije čije je najvažnije stanište zemlja. Pri rastu na čvrstim podlogama i u submerznim uslovima grade supstratni i vazdušni micelijum. Morfološka diferencijacija je praćena produkcijom sekundarnih metabolita kao što su antibiotici, a i različitih hidrolitičkih enzima. Za mikroorganizme koji ih proizvode antibiotici predstavljaju kompetitivno oružje, agense za transport metala kao i efektore diferencijacije. Proteolitički enzimi, takođe, imaju određenu ulogu u razvojnom ciklusu aktinomiceta. Na primer, uključeni su u procese građenja vazdušnog micelija i sporulaciju. Soj Streptomyces hygroscopicus CH-7 pri fermentaciji proizvodi antibiotike poliketidne strukture i smesu ekstracelularnih proteolitičkih enzima. U ovom radu je ispitivan uticaj antibiotika rifamicina i hloramfenikola, inhibitora transkripcije i translacije, na produkciju polienskog antibiotika heksaena H-85 i proteolitičkih enzima. Inhibited su dodavani pri inokulaciji (O h) i u različitim vremenskim intervalima fermentacije (12-48 h). Dejstvom antibiotika inhibitora transkripcije i translacije utvrdjeno je da se enzim polien sintetaza transkribuje do 12. časa, a translacija teče do 48. časa fermentacije. Dodatak rifamicina pri zasejavanju drastično snižava proteolitičku aktivnost, a u kasnijim fazama izaziva smanjenje (36-80%). Hloramfenikol smanjuje produkciju tripsinu slične proteaze. ali nema dejstvo na aminopeptidaznu aktivnost. Rifamicin i hloramfenikol ne pokazuju značajno inhibitorno dejstvo na rast soja

The influence of Al3+ion on porcine pepsin activity in vitro

The in vitro effect of Al3+ ions in the concentration range 1.710-6M-8.710-3M on pepsin activity at pH 2, via kinetic parameters and its electrophoretic mobility was evaluated. Kinetic study demonstrated the existence of an activation effect of Al3+ at pH 2 on pepsin molecule. Kinetic analysis with respect to concentrations of haemoglobin showed that Al3+ ions increase the maximal velocity (Vmax) and kcat values rather than apparent affinity for substrate (KS) implying the non-competitive nature of activation which indicated that aluminium was a non-essential activator of partial non-competitive type. The values of the equilibrium constants KS and KmA for dissociation of corresponding complexes were evaluated as 0.9040.083mM and 8.560.51M, respectively. Dissociation constant KA, of activator from enzyme-activator complex calculated via kinetic and direct measurement of Al3+ binding data, as well as activation constant A50, the activator concentration that gives a rate equal to half at a saturating concentration of activator, were found to be 8.820.90M, 8.390.76M, and 8.050.48M respectively. Native PAGE electrophoresis shows the decrease in electrophoretic mobility of pepsin and confirms modification of the electric charge and conformational changes of pepsin caused by bound Al3+ on the pepsin molecule. Al3+ induced conformational changes of pepsin were verified by UV-VIS and IR spectra. Moreover, the absence of conformational changes in the haemoglobin molecule in the presence of Al3+ ions confirms that the obtained activation is a consequence of conformational changes caused only in the pepsin molecule

Supplementary data for the article: Izrael Živković, L. T.; Živković, L. S.; Beškoski, V. P.; Gopčević, K. R.; Jokić, B. M.; Radosavljević, D. S.; Karadžić, I. M. The Candida Rugosa Lipase Adsorbed onto Titania as Nano Biocatalyst with Improved Thermostability and Reuse Potential in Aqueous and Organic Media. Journal of Molecular Catalysis B: Enzymatic 2016, 133, S533–S542. https://doi.org/10.1016/j.molcatb.2017.06.001

Supplementary material for: [https://doi.org/10.1016/j.molcatb.2017.06.001]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/315]Related to accepted version: [http://cherry.chem.bg.ac.rs/handle/123456789/3648

Analysis of thermal denaturation of pepsin on basis of MALDI-TOF MS and PAGE experimental data

To obtain detailed information about properties of pepsin in thermal denaturing conditions, polyacrylamide gel electrophoresis (PAGE) and matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF MS) experimental data were analyzed. These methods were used to analyze the changes in the structural properties of pepsin molecule subjected to broad-range temperature variations, from 25 ºC to 70 ºC, and pH range from 1 to 4.Physical chemistry 2012 : 11th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 24-28 September 201

Efekti antibiotika koji deluju na ćelijske membrane na srce pacova

The effect of some membrane active ionophoric antibiotics on the amplitude of contractions of isolated rat heart right ventricle was studied. The effects of polyether nigericin, polyene amphotericin B and peptide antibiotic polymyxin B were examined. Nigericin in a concentration of 1.38 _mol/L exerts a positive inotropic effect with its maximal value (+29%) 15 minutes after application. Amphotericin B in a concentration of 1.08 _mol/L caused a positive inotropic effect, which was maximal in the 30th minute of the experiment (+28%). Polymyxin B in a concentration of 0.84 _mol/L caused a positive inotropic effect, which was maximal (+32%) 20 minutes after application.Amfotericin B, nigericin i polimiksin B pokazuju pozitivni inotropni efekat na izolovanu desnu komoru srca pacova. Imajući u vidu nižu toksičnost jonofornih antibiotika u poređenju sa glikozidnim supstancama koje se u farmakoterapiji koriste kao kardiotonici i visoku selektivnost jonofora prema nekim katjonima, dobijeni rezultati ukazuju na moguću upotrebu ovih supstanci u poboljšanju funkcije insuficijentnog miokarda

Candida rugosa lipase immobilized onto titania as nanobiocatalyst in organic solvent

Kinetic measurements can be used to predict the optimum kinetic behaviour of a particular biocatalyst. Based on those predictions, optimisation of biocatalytic reactions, as well as process design to improve productivity and reduce the cost of various processes can be performed.V International Conference on Radiation in Various Fields of Research : RAD 2017 : book of abstracts; June 12-16, 2017; Budva, Montenegr