research centers


Search results: Found 3

Listing 1 - 3 of 3
Sort by

Article
Purification and characterization of hemolysin produced by a local isolates of Staphylococcus aureus

Authors: Mohammed I. Nadir --- Hussain S. Al-Hassani --- Amer H. Al-Shammary
Journal: Karbala Journal of Medicine مجلة كربلاء الطبية ISSN: 19905483 Year: 2012 Volume: 5 no 2 Issue: 12 Pages: 1455-1463
Publisher: Kerbala University جامعة كربلاء

Loading...
Loading...
Abstract

background: Staphylococcus aureus is a ubiquitous bacterium that is generating increasingly bad press coverage due to its propensity to adopt a pathogenic lifestyle in hospital and community settings. S. aureus colonies are found in approximately 30% of the general population. It colonizes the skin readily and can lead to a wide range of pathological conditions from skin lesions to osteomyelitis, endocarditis, and septicemia. Hemolysins are extracellular toxic proteins which are produced by many gram negative (e.g. Escherichia coli, Serratia spp., Proteus spp., Vibrio spp., Pasteurella spp., Pseudomonas aeruginosa) and gram positive bacteria (e.g. Streptococcus spp., Staphylococcus aureus, Listeria spp., Bacillus cerius, Clostridium tetani), all of which possess a certain pathogenic potential. Hemolysins have been therefore always considered as virulence factors. Most hemolysins cause lysis of erythrocytes by forming pores of varying diameters in the membrane and are designated as such because they have the ability to lyse red blood cells (RBCs). Objectives1-Purification of hemolysin from a local isolate of S. aureus.2-Characterization of hemolysin produced by a local isolate of S. aureus.Methods: Bacterial samples were identified by subjecting them to the standard laboratory procedures while semi quantitative screening on blood agar (containing 5% human blood) revealed that all isolates were hemolysin producer but in different efficiencies. Hemolysin was extracted by cooling centrifugation and purified by many steps including: precipitation by ammonium sulphate, dialysis, ionic exchange chromatography by using DEAE-Cellulose, and gel filtration chromatography by using Sephadex G-100. The molecular weight of hemolysin was determined by gel filtration chromatography on Sephadex G-100 while the optimum pH and temperature for hemolysin stability were also determined.Results: The results showed that forty isolates out of 100 were identified as Staphylococcus aureus. Hemolysin was extracted by cooling centrifugation and purified by many steps including: precipitation by ammonium sulphate with 50-75% saturation percentage, dialysis, ionic exchange chromatography by using DEAE-Cellulose, and gel filtration chromatography by using Sephadex G-100. The results showed that hemolysin was purified 135 fold with a yield of 1.16%.The molecular weight of hemolysin determined by gel filtration chromatography on Sephadex G-100 column was about 35000 daltons, while the optimum pH for enzyme stability was 7 and the optimum temperature for enzyme stability was between 25-35oC.Conclusions1.Conventional methods can be performed to extract hemolysins.2.Hemolysin was maximally produced when the pH was near neutrality and incubation temperature was 37oC and this conclusion indicates that hemolysin was produced when the conditions were similar to that of the host.


Article
EXTRACTION, PURIFICATION AND CHARACTERIZATION OF LIPASE PRODUCED BY A LOCAL ISOLATE OF STAPHYLOCOCCUS AUREUS

Authors: Amer H.R. Al-Shammary عامر هاني رزاق الشمري --- Asia F.R. Al-Husseiny اسيا فاضل رضا الحسيني
Journal: IRAQI JOURNAL OF MEDICAL SCIENCES المجلة العراقية للعلوم الطبية ISSN: P16816579,E22244719 Year: 2014 Volume: 12 Issue: 3 Pages: 254-260
Publisher: Al-Nahrain University جامعة النهرين

Loading...
Loading...
Abstract

Background:Staphylococcus aureus is a ubiquitous bacterium that is generating increasingly bad press coverage due to its propensity to adopt a pathogenic lifestyle in hospital and community settings. Lipases catalyze both the hydrolysis and synthesis of triacylglycerols. Many of these enzymes are characterized by stability at high temperatures and in organic solvents.Objective:Purification of the enzyme by using the conventional methods and characterization of lipase.Methods:Purification included: extraction of the enzyme, the precipitation of the enzyme by ammonium sulphate, dialysis, ionic exchange chromatography by using DEAE-Cellulose (Diethylaminoethyl-Cellulose), and gel filtration by using Sephacryl S-200. Equal amounts of purified lipase solution were mixed with PBS (Phosphate buffer sodium) solutions of different pH (4,5,... until 10) and incubated in a water bath at 37 oC for 30 minutes, then the lipase activity was estimated. The purified lipase was incubated at different degrees of temperature (5, 15, ...until 85 oC) for 30 minutes. The molecular weight was determined by gel filtration chromatography.Results:The results revealed that the crude enzyme solution had a total protein concentration of 21.3 mg/ml and an enzyme activity of 257 µmole/ml. The lipase was precipitated by ammonium sulphate with 50-75%. Then the protein concentration was 4.7 mg/ml while the enzyme activity was 812 µmole/ml. Revealed that the protein concentration was 2.3 mg/ml and enzyme activity was 1020 µmole/ml. This revealed that the protein concentration was 0.9 mg/ml and the enzyme activity was 1669 µmole/ml.Conclusion:Lipase was purified to a considerable homogeneity and the characterization experiments revealed that the enzyme showed considerable heat stability and was optimally active at alkaline pH.Key words:Lipase, ion exchange chromatography, gel filtration chromatography, molecular weight.


Article
A Comparative Study of Superoxide Dismutase Purification from Red Blood Cells of Near Residents to Cellular Phone Base-Stations Antennas
دراسة مقارنة لتنقية انزيم سوبراوكسايد ديسميوتيز من كريات الدم الحمراء للاشخاص القاطنين قريبا من مرسلات محطات الهاتف الخلوي

Author: Ali Haneen Ismeer علي حنين اسمير
Journal: Univesity of Thi-Qar Journal مجلة جامعة ذي قار العلمية ISSN: 66291818 Year: 2015 Volume: 10 Issue: 1 Pages: 1-10
Publisher: Thi-Qar University جامعة ذي قار

Loading...
Loading...
Abstract

Superoxide dismutase (SOD) is the first line of defense against reactive oxygen species (ROS) such as the superoxide radical which is a toxic to living cells as it oxidizes and degrades biological molecules such as lipids and proteins. In the present study, SOD was purified from red blood cells (RBCs) of individuals who were living nearby the cellular phone base-station and others who living far from these stations. Over the last 10 years, there has been a wide spread in the use of cellular phones in Iraq, the communication system which can require hundreds of antennas in close proximity to the population with exposure to the radiation. The emitted radiation from these antennas may affect the biological systems. The aim of this work was to comprise the purification of SOD from RBCs of two individual groups. The first group (G1) was included individuals who reside near from mobile phone base-station, and the second group (G2) was included the individuals who inhabit far from these stations. We applied a simple and rapid procedure for the purification by ion exchange chromatography on diethylaminoethyl (DEAE)-Sepharose column. SOD was purified with a fold of purification of 20.6, yield of 47.5 %, SOD specific activity was 2948 (U/mg) for G1, while for the G2 the fold of purification was equal to 15.4 with a yield of 20.6% and 2143 (U/mg) as a specific activity of SOD. This procedure appears, therefore, to be a convenient and easily method for isolating this enzyme.

يعتبر انزيم سوبراوكسايد ديسميوتيز خط الدفاع الاول ضد الاصناف الاوكسيجينية الفعالة مثل جذر السوبراوكسيد السام للخلايا الحية بسبب قدرته على اكسدة وتكسير الجزيئات الحيوية كالدهون والبروتينات. في هذه الدراسة نقي انزيم انزيم سوبراوكسايد ديسميوتيز من كريات الدم الحمراء للاشخاص الساكنين بجوار مرسلات الهاتف الخلوي والاشخاص البعيدين عن تلك المرسلات. خلال العشرة اعوام الاخيرة استخدمت الهواتف الخلوية بشكل واسع في العراق، تلك التقنية التي تتطلب المئات من المرسلات القريبة من التجمعات السكانية معرضة اياهم للاشعاع. الاشعة المنبعثة من تلك المرسلات ممكن ان تؤثر على الانظمو البايولوجية.الهدف من الدراسة هو مقارنة عملية تنقية انزيم سوبراوكسايد ديسميوتيز من كريات الدم الحمراء جمعت من مجموعتين من الاشخاص، الاولى (ج1) تضمنت الاشخاص المجاورين لمرسلات الهاتف الخلوي (بحدود 100 متر2) لمدة لاتقل عن ثلاث سنوات، بينما المجموعة الثانية (ج2) كانت متضمنة الاشخاص الساكنين بعيدا عن تلك المرسلات. لقد طبقت هنا طريق بسيطة وسريعة لتنقية الانزيم بواسطة كروماتوغرافيا التبادل الايوني على عمود ثنائي اثيل امينواثيل سيفاروز. نقي الانزيم بعدد مرات التنقية قدرها 20.6، حصيلة مقدارها 47.5% وفعلية نوعية للانزيم قدرها 2948 (وحدة/مغم) للمجموعة الاولى، بينما كانت النتائج للمجموعة الثانية هي 15.4 من مرات التنقية بحصيلة قدرها 20.6% ، وفعلية نوعية للانزيم قدرها 2143 (وحدة/مغم).

Listing 1 - 3 of 3
Sort by
Narrow your search

Resource type

article (3)


Language

English (2)

Arabic and English (1)


Year
From To Submit

2015 (1)

2014 (1)

2012 (1)