John Westley (biochemist)
{{short description|American enzymologist}}
{{distinguish|John Wesley}}
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| birth_date = 1927
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| fields = Biochemistry
| workplaces = University of Chicago
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| education = University of Chicago (Ph.D. 1954)
| thesis_title = Studies on the synthesis of histidine by Escherichia coli
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| thesis_year = 1954
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| known_for = Studies of enzyme kinetics, especially of sulfurtransferases
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| footnotes = A photograph may be found at https://photoarchive.lib.uchicago.edu/db.xqy?one=apf1-13257.xml, but cannot be displayed here on account of copyright restrictions
}}John W. Westley (1927–) was an enzymologist at the University of Chicago, best known for his research on rhodanese and other sulfurtransferases.
Education and employment
John Westley obtained his Ph.D. in 1954 at the University of Chicago on the basis of a thesis entitled "Studies on the synthesis of histidine by Escherichia coli".{{cite thesis | url = http://pi.lib.uchicago.edu/1001/cat/bib/4030139 | title = UChicago Library Catalog | date = 1954 | oclc = 83351841 | last1 = Westley | first1 = John | last2 = Westley | first2 = John }} He subsequently worked in the Department of Biochemistry (now Department of Biochemistry & Molecular Biology) of the University of Chicago.
Research
John Westley's doctoral research concerned the biosynthesis of histidine in Escherichia coli. Subsequently he became an enzymologist and worked principally on rhodanese (thiosulfate sulfurtransferase, EC 2.8.1.1), starting with a comparison of the enzyme forms isolated from beef liver and kidney{{cite journal | pmid = 13672976| title = A Comparison of Some Biochemical Properties of the Beef Liver and Beef Kidney Rhodaneses|first= John|last = Westley| journal = J. Biol. Chem. | volume = 234| number = 7|year = 1959|pages = 1857–1860
| doi = 10.1016/S0021-9258(18)69938-7| doi-access = free}} and purification of the kidney enzyme.{{cite journal
| pmid= 13844173| title = Crystalline Beef Kidney Rhodanese|first1= John|last1 = Westley|first2 = John R.|last2 = Green| journal = J. Biol. Chem.|volume =234|number=9|pages = 2325–2326|year=1959
| doi = 10.1016/S0021-9258(18)69808-4| doi-access = free}}
He continued to study the kinetic behaviour of the liver enzyme,{{cite journal
| doi= 10.1021/bi00713a006
| pmid = 4858225
|title = Human liver rhodanese. Nonlinear kinetic behavior in a double displacement mechanism|first1 = R.|last1 = Jarabak|first2= J.|last2 = Westley|journal = Biochemistry |year = 1974|volume=13|number=16|pages = 3233–3236
}} and was probably the first to study memory effects in substituted-enzyme ("ping-pong") mechanisms.{{cite journal | doi= 10.1021/bi00713a007|title = Enzymic memory. Consequence of conformational mobility | first1 = Rebecca | last1 = Jarabak | first2 = John | last2 = Westley | journal = Biochemistry | year=1974 | volume = 13 |number = 16 |pages = 3237–3239|pmid = 4842741 }}{{cite journal
| pmid=479184
|title = Enzymic memory. Steady state kinetic and physical studies with ascorbate oxidase and aspartate aminotransferase|journal =J. Biol. Chem.|year = 1979|volume=254 |number=18|pages=9142–9147|first1 = M.|last1 =Katz |first2 = J.|last2 = Westley.
| doi= 10.1016/S0021-9258(19)86822-9| doi-access=free }} Memory effects are also possible in ternary-complex mechanisms, as in the "mnemonical model" used by Ricard and co-workers to explain the deviations from linear kinetics observed in wheat-germ hexokinase.{{cite journal
| doi=10.1111/j.1432-1033.1974.tb03826.x
|journal = Eur. J. Biochem.|volume= 49|number= 1| pages = 209–223
|title = Regulatory Behavior of Monomeric Enzymes 2. A Wheat-Germ Hexokinase as a Mnemonical Enzyme
|first1 = Jean-Claude| last1 = Meunier
|first2 = Jean | last2 = Buc
|first3 = André | last3 = Navarro
|first4 = Jacques | last4 = Ricard
|year = 1974
| pmid=4617677 }} However, the kinetic effects are completely different. The memory effects discussed by Katz and Westley, do not generate departures from linear kinetics but instead allow an enzyme to "remember" which of various alternative substrates it handled in the previous catalytic cycle and modify its kinetic properties accordingly. In addition to specific reports on sulfurtransferases he wrotre a review on these enzymes.{{cite journal
| doi= 10.1016/S0272-0590(83)80008-6| journal = Fundam. Appl. Toxicol.| volume = 3| number= 5|year = 1983| pages = 377–382 |title = The sulfurtransferases |first1 = John |last1 =Westley |first2 = Howard |last2 = Adler |first3 = Laura |last3 = Westley |first4 = Craig |last4 = Nishida
| pmid = 6357923}}
Westley was also concerned with more general aspects of enzyme kinetics, such as uncompetitive inhibition in metabolic systems,{{cite journal
| doi= 10.1074/jbc.271.10.5347 | title = Enzyme inhibition in open systems: Superiority of uncompetitive agents |journal = J. Biol. Chem. |first1 = Aiko|last1 = Westley |first2 = John|last2 = Westley| volume = 271|number=19|pages = 5347–5352 | year = 1996
| doi-access = free | pmid = 8621387 }} metabolite channelling,{{cite journal
| doi= 10.1021/bi00003a028 | journal = Biochemistry | title = Sulfate-Activating Enzymes in Normal and Brachymorphic Mice: Evidence for a Channeling Defect | volume = 34 | number = 3 | pages = 940–945| first1 = Stephen | last1 = Lyle| first2 = Jeffrey D. | last2 = Stanczak| first3 = John | last3 = Westley| first4 = Nancy B. | last4 = Schwartz | year = 1995
| pmid = 7827052 }} and rapid-equilibrium mechanisms,{{cite journal
| doi= 10.1021/ed062p656
| title = Rapid equilibrium-ordered enzyme mechanisms
| journal = J. Chem. Educ. | volume = 62|number = 8 | pages = 656
| first1 = Thomas | last1 = Chauncey
| first2 = Rebecca | last2 = Jarabak
| first3 = John | last3 = Westley | year = 1985
| bibcode = 1985JChEd..62..656C
}} and regulation.{{cite journal
| doi= 10.1016/0065-2571(75)90024-2
| journal = Adv. Enz. Reg.
| year = 1975 | volume = 13| pages = 339–353
| title = Origins of regulatory behavior
| first1 = John | last1 = Westley |first2 = Hugh |last2 = Taylor
| pmid = 1211291
}}
''Enzymic catalysis''
In addition to his research publications, Westley is also known for his book Enzymic catalysis,{{cite book |last1=Westley |first1=John |title= Enzymic Catalysis |date= 1969|publisher=Harper & Row}} which in its time was the leading textbook on the subject.
References
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Category:American textbook writers