Pub Date : 2000-05-01DOI: 10.1016/S0307-4412(00)00029-7
Chris G. Whiteley
A graphical method for analysing enzyme data to obtain kinetic parameters, to identify the types of inhibition and the enzyme mechanisms is described. The method consists of plotting experimental data as v/(V0−v) versus 1/(I) at different substrate concentrations. I is the inhibitor concentration; V0 and v are the initial rates of enzyme reaction attained by the system in the presence of a fixed amount of substrate and in the absence and presence of inhibitor respectively. Complete inhibition gives straight lines that pass through the origin while partial inhibition gives straight lines that converge on the 1/I-axis at a point away from the origin. With uncompetitive inhibition the slopes of the lines decrease with increasing substrate concentration. The kinetic parameters Km, K′i and β (degree of partiality) can best be determined from respective secondary plots of slope and intercept versus reciprocal of substrate concentration.
{"title":"Enzyme kinetics: partial and complete uncompetitive inhibition","authors":"Chris G. Whiteley","doi":"10.1016/S0307-4412(00)00029-7","DOIUrl":"10.1016/S0307-4412(00)00029-7","url":null,"abstract":"<div><p>A graphical method for analysing enzyme data to obtain kinetic parameters, to identify the types of inhibition and the enzyme mechanisms is described. The method consists of plotting experimental data as <em>v</em>/(<em>V</em><sub>0</sub>−<em>v</em>) versus 1/(<em>I</em>) at different substrate concentrations. I is the inhibitor concentration; <em>V</em><sub>0</sub> and v are the initial rates of enzyme reaction attained by the system in the presence of a fixed amount of substrate and in the absence and presence of inhibitor respectively. Complete inhibition gives straight lines that pass through the origin while partial inhibition gives straight lines that converge on the 1/<em>I</em><span>-axis at a point away from the origin. With uncompetitive inhibition the slopes of the lines decrease with increasing substrate concentration. The kinetic parameters </span><em>K</em><sub>m</sub>, <em>K</em>′<sub>i</sub> and <em>β</em> (degree of partiality) can best be determined from respective secondary plots of slope and intercept versus reciprocal of substrate concentration.</p></div>","PeriodicalId":80258,"journal":{"name":"Biochemical education","volume":"28 3","pages":"Pages 144-147"},"PeriodicalIF":0.0,"publicationDate":"2000-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0307-4412(00)00029-7","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21721011","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
An experiment on the use of problem-based exercises in an Indian Medical School is described. Problem-based classes were supplemented with laboratory classes and feedback from both students and tutors was analyzed.
{"title":"Problem-oriented small-group discussion in the teaching of biochemistry laboratory practicals.","authors":"Das, Sinha","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>An experiment on the use of problem-based exercises in an Indian Medical School is described. Problem-based classes were supplemented with laboratory classes and feedback from both students and tutors was analyzed.</p>","PeriodicalId":80258,"journal":{"name":"Biochemical education","volume":"28 3","pages":"154-155"},"PeriodicalIF":0.0,"publicationDate":"2000-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21721014","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2000-05-01DOI: 10.1016/S0307-4412(99)00139-9
Carlos A. Stella, Daniel A. Sáenz, Mónica S. Chianelli, Sebastián Kaminszczik
The present article describes a simple protocol that allows the study of nitrogen source utilisation by cells and its relation with cellular growth. The assay can be performed using the minimum of laboratory equipment.
{"title":"A simple protocol to evaluate nitrogen utilisation in Saccharomyces cerevisiae","authors":"Carlos A. Stella, Daniel A. Sáenz, Mónica S. Chianelli, Sebastián Kaminszczik","doi":"10.1016/S0307-4412(99)00139-9","DOIUrl":"10.1016/S0307-4412(99)00139-9","url":null,"abstract":"<div><p>The present article describes a simple protocol that allows the study of nitrogen source utilisation by cells and its relation with cellular growth. The assay can be performed using the minimum of laboratory equipment.</p></div>","PeriodicalId":80258,"journal":{"name":"Biochemical education","volume":"28 3","pages":"Pages 169-170"},"PeriodicalIF":0.0,"publicationDate":"2000-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0307-4412(99)00139-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21721018","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2000-05-01DOI: 10.1016/S0307-4412(99)00107-7
Hérica de Lima Santos, Pietro Ciancaglini
The main objective of this laboratory practical class was to teach students how a detergent and the best experimental conditions are chosen to solubilize a given membrane protein. Kidney Na,K-ATPase was chosen as the protein of interest and anionic, neutral and zwitterionic detergents were tested. Simple laboratory experiments were designed to study the effect of the detergent on the activity of the enzyme, the effect of detergent concentration on solubilization, the effect of protein concentration on enzyme solubilization, and the effect of time and temperature of incubation during enzyme solubilization. This resulted in the selection of an appropriate detergent for the solubilization of the protein taking into account smaller inactivation factors, more effective solubilization (more effective solubilization with a better detergent–protein relationship), lower inactivation temperature and time of incubation of the membrane protein with the detergent. The results obtained showed that instantaneous incubation of Na,K-ATPase with C12E8 (1 : 1 w/w) at 4°C resulted in a more efficient solubilization and had a smaller denaturing effect on the solubilized enzyme.
本实验课的主要目的是教学生如何选择一种洗涤剂和最佳实验条件来溶解给定的膜蛋白。选择肾Na, k - atp酶作为感兴趣的蛋白质，并测试了阴离子，中性和两性离子洗涤剂。设计简单的室内实验，研究了洗涤剂对酶活性的影响、洗涤剂浓度对增溶作用的影响、蛋白质浓度对酶增溶作用的影响以及酶增溶过程中孵育时间和温度的影响。这导致选择合适的洗涤剂来增溶蛋白质，同时考虑到更小的失活因子，更有效的增溶(更有效的增溶与更好的洗涤剂-蛋白质关系)，更低的失活温度和膜蛋白与洗涤剂的孵育时间。结果表明，在4℃条件下，C12E8 (1:1 w/w)瞬时孵育Na, k - atp酶的增溶效率更高，且对增溶酶的变性影响较小。
{"title":"A practical approach to the choice of a suitable detergent and optimal conditions for solubilizing a membrane protein","authors":"Hérica de Lima Santos, Pietro Ciancaglini","doi":"10.1016/S0307-4412(99)00107-7","DOIUrl":"10.1016/S0307-4412(99)00107-7","url":null,"abstract":"<div><p><span>The main objective of this laboratory practical class was to teach students how a detergent and the best experimental conditions are chosen to solubilize a given membrane protein. Kidney Na,K-ATPase was chosen as the protein of interest and anionic, neutral and zwitterionic detergents were tested. Simple laboratory experiments were designed to study the effect of the detergent on the activity of the enzyme, the effect of detergent concentration on solubilization, the effect of protein concentration on enzyme solubilization, and the effect of time and temperature of incubation during enzyme solubilization. This resulted in the selection of an appropriate detergent for the solubilization of the protein taking into account smaller inactivation factors, more effective solubilization (more effective solubilization with a better detergent–protein relationship), lower inactivation temperature and time of incubation of the membrane protein with the detergent. The results obtained showed that instantaneous incubation of Na,K-ATPase with C</span><sub>12</sub>E<sub>8</sub> (1<!--> <!-->:<!--> <!-->1 w/w) at 4°C resulted in a more efficient solubilization and had a smaller denaturing effect on the solubilized enzyme.</p></div>","PeriodicalId":80258,"journal":{"name":"Biochemical education","volume":"28 3","pages":"Pages 178-182"},"PeriodicalIF":0.0,"publicationDate":"2000-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0307-4412(99)00107-7","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"56623675","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Maté, Aledo, Pérez-Gómez, Esteban del Valle A, Segura
This article describes a method for determining some antioxidant enzyme activities (catalase and/or glutathione peroxidase) and the oxidative status (protein oxidative damage and/or lipid peroxidation) of human blood. However, the main objective of the work is to illustrate the relationship between antioxidant defences and oxidative damage, showing to students their correlation and the general importance of the biochemical regulation in health and diseases.
{"title":"Interrelationship between oxidative damage and antioxidant enzyme activities: an easy and rapid experimental approach.","authors":"Maté, Aledo, Pérez-Gómez, Esteban del Valle A, Segura","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>This article describes a method for determining some antioxidant enzyme activities (catalase and/or glutathione peroxidase) and the oxidative status (protein oxidative damage and/or lipid peroxidation) of human blood. However, the main objective of the work is to illustrate the relationship between antioxidant defences and oxidative damage, showing to students their correlation and the general importance of the biochemical regulation in health and diseases.</p>","PeriodicalId":80258,"journal":{"name":"Biochemical education","volume":"28 2","pages":"93-95"},"PeriodicalIF":0.0,"publicationDate":"2000-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21575434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2000-03-01DOI: 10.1016/S0307-4412(99)00128-4
Jennelle Kyd
Post graduate research students need to undertake programs that will develop their potential as a scientist. They need to acquire skills to develop scientific argument, design an experimental approach to test a hypothesis, obtain and analyse data, and effectively communicate their ideas and findings to the scientific community. Many biotechnology-based programs are now funded by industry partnerships and integrating post graduate students into these programs require special considerations.
{"title":"Integration of post-graduate studies with corporately funded biotechnology programs","authors":"Jennelle Kyd","doi":"10.1016/S0307-4412(99)00128-4","DOIUrl":"10.1016/S0307-4412(99)00128-4","url":null,"abstract":"<div><p>Post graduate research students need to undertake programs that will develop their potential as a scientist. They need to acquire skills to develop scientific argument, design an experimental approach to test a hypothesis, obtain and analyse data, and effectively communicate their ideas and findings to the scientific community. Many biotechnology-based programs are now funded by industry partnerships and integrating post graduate students into these programs require special considerations.</p></div>","PeriodicalId":80258,"journal":{"name":"Biochemical education","volume":"28 2","pages":"Pages 86-88"},"PeriodicalIF":0.0,"publicationDate":"2000-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0307-4412(99)00128-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21575534","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2000-03-01DOI: 10.1016/S0307-4412(99)00099-0
Jose M. Maté, J.Carlos Aledo, Cristina Pérez-Gómez, Alicia Esteban del Valle, Jose M. Segura
This article describes a method for determining some antioxidant enzyme activities (catalase and/or glutathione peroxidase) and the oxidative status (protein oxidative damage and/or lipid peroxidation) of human blood. However, the main objective of the work is to illustrate the relationship between antioxidant defences and oxidative damage, showing to students their correlation and the general importance of the biochemical regulation in health and diseases.
{"title":"Interrelationship between oxidative damage and antioxidant enzyme activities: an easy and rapid experimental approach","authors":"Jose M. Maté, J.Carlos Aledo, Cristina Pérez-Gómez, Alicia Esteban del Valle, Jose M. Segura","doi":"10.1016/S0307-4412(99)00099-0","DOIUrl":"10.1016/S0307-4412(99)00099-0","url":null,"abstract":"<div><p>This article describes a method for determining some antioxidant enzyme activities (catalase and/or glutathione peroxidase) and the oxidative status (protein oxidative damage and/or lipid peroxidation) of human blood. However, the main objective of the work is to illustrate the relationship between antioxidant defences and oxidative damage, showing to students their correlation and the general importance of the biochemical regulation in health and diseases.</p></div>","PeriodicalId":80258,"journal":{"name":"Biochemical education","volume":"28 2","pages":"Pages 93-95"},"PeriodicalIF":0.0,"publicationDate":"2000-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0307-4412(99)00099-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"56623372","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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