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Hindawi Publishing CorporationJournal of ChemistryVolume 2013 Article ID 120480 4 pageshttpdxdoiorg1011552013120480

Research ArticleA Comparative Study on the Interaction of Sulfonamide andNanosulfonamide with Human Serum Albumin

G Rezaei Behbehani1 Moayed Hossaini Sadr2 H Nabipur2 and L Barzegar3

1 Chemistry Department Imam Khomeini International University Qazvin Iran2Chemistry Department Faculty of Science Azarbaijan Shahid Madani University Tabriz Iran3Chemistry Department Faculty of Science Islamic Azad University Takestan Branch Takestan Iran

Correspondence should be addressed to G Rezaei Behbehani grb402003yahoocom

Received 22 June 2012 Revised 27 November 2012 Accepted 11 December 2012

Academic Editor Yoshihiro Kudo

Copyright copy 2013 G Rezaei Behbehani et al is is an open access article distributed under the Creative Commons AttributionLicense which permits unrestricted use distribution and reproduction in any medium provided the original work is properlycited

Binding parameters of theN-phenyl benzene sulfonyl hydrazide sulfonamide andnanosulfonamide interactionwith human serumalbumin were determined by calorimetry method e obtained binding parameters indicated that sulfonamide in the secondbinding sites has higher affinity for binding than the rst binding sitese binding process of sulfonamide to HSA is both enthalpyand entropy driven e associated equilibrium constants conrm that sulfonamide binds to HSA with high affinity (22 times 106and 386105Mminus1 for rst and second sets of binding sites resp) e obtained results indicate that sulfonamide increases the HSAantioxidant property Nanosulfonamide has much more affinity for HSA (36 times 106 Mminus1) than sulfonamide

1 Introduction

Physicochemical properties of nanoparticles such as theirsmall size large surface area surface charge and abil-ity to make them potential delivery systems for effectivetreatments e pharmacokinetic parameters of therapeuticdrugs against the diseases show limitations in their efficacye poor bioavailability side effects due to the high dosesadministered long treatment and the emergence of drugresistant strains are the disadvantages of ordinary drugs eadvances that nanotechnology-based drug delivery systemshave made in improving the pharmacokinetics and efficacyof therapeutic drugs [1ndash4]

Sulfonamides were the rst chemical substances system-atically used to treat and prevent bacterial infections inhumans Sulfonamides are bacteriostatic drugs they work byinhibiting the growth and multiplication of bacteria withoutkilling them Currently their most common use in humansis treating urinary tract infections [5] ey are estimatedto be 16ndash21 of annual antibiotic usage making them themost important group of antibiotics consumed by humans[6] Sulfonamides are compounds that contain sulfur in a

SO2NH2moiety directly attached to a benzene ringe termldquosulfa allergyrdquo is oen incorrectly applied to all adverse reac-tions that occur with sulfonamide-containing medicationsand not just to those due to hypersensitivity mechanismsPatients who experience side effects such as nausea andvomiting may interpret this as an allergy and subsequentlyreport that they are allergic to sulfas [7] e binding ofthe sulfonamides to serum albumins an important factorof the pharmacokinetic of these drugs has been extensivelystudied by several workers especially regarding the extent ofbinding the stoichiometry and the inuence of the chemicalstructure on the binding But only little information isavailable on the mechanism of the binding and on the natureof the sulfonamide-albumin complex Some workers haveshown a correlation between the partition coefficients of thesulfonamides and the extent of the binding and concludedthat the binding is mainly hydrophobic [8] In this work wecompared the most comprehensive study on the interactionsof sulfonamide and nanosulfonamide (N-phenyl benzenesulfonyl hydrazide) with HSA for further understanding of

2 Journal of Chemistry

their effects on the stability and the structural changes of theHSA molecules

2 Materials andMethod

Human serum albumin (HSAMW= 66411 grmol) and Trisbuffer used were of analytical grade with the highest purityavailable without any purication Sulfonamide derivative(N-phenyl benzene sulfonyl hydrazide) was synthesizede isothermal titrationmicrocalorimetric experiments wereperformed with the four-channel commercial microcalori-metric system Sulfonamide and nanosulfonamide solutions(16129 120583120583M) were injected by the use of a Hamilton syringeinto the calorimetric titration vessel which contained 18mLHSA (6022 120583120583M) Injection of sulfonamide solution intothe perfusion vessel was repeated 29 times with 10120583120583Lper injection e calorimetric signal was measured by adigital voltmeter that was part of a computerized recordingsystem e heats of each injection was calculated by theldquoermometric Digitam 3rdquo soware program e heat ofdilution of the sulfonamide and nanosulfonamide solutionswere measured as described above except HSA was excludede microcalorimeter was frequently calibrated electricallyduring the course of the study

3 Results and Discussion

We have shown previously that the heats of the ligand +HSA interactions in the aqueous solvent mixtures can becalculated via the following equation [9ndash14]

119902119902 119902 119902119902max119909119909prime119861119861 minus 120575120575

120579120579119860119860 10076511007651119909119909

prime119860119860119871119871119860119860 + 119909119909

prime11986111986111987111987111986111986110076671007667

minus 10076501007650120575120575120579120579119861119861 minus 12057512057512057912057911986011986010076661007666 10076511007651119909119909

prime119860119860119871119871119860119860 + 119909119909

prime11986111986111987111987111986111986110076671007667 119909119909

prime119861119861

(1)

where 119902119902 are the heats of sulfonamide + HSA or nanosulfon-amide +HSA interactions and 119902119902max represents the heat valueupon saturation of all HSA e parameters 120575120575120579120579119860119860 and 120575120575120579120579119861119861 arethe indexes of HSA stability in the low and high sulfonamideconcentrations respectively Cooperative binding requiresthat themacromolecule hasmore than one binding site sincecooperativity results from the interactions between identicalbinding sites with the same ligand If the binding of a ligandat one site increases the affinity for that ligand at anothersite then the macromolecule exhibits positive cooperativityConversely if the binding of a ligand at one site lowersthe affinity for that ligand at another site then the enzymeexhibits negative cooperativity If the ligand binds at each siteindependently then the binding is noncooperative 119901119901 119901 119901or 119901119901 119901 119901 indicate positive or negative cooperativity of amacromolecule for binding with a ligand respectively 119901119901 119902119901 indicates that the binding is noncooperative 119909119909prime119861119861 can beexpressed as follows

119909119909prime119861119861 119902119901119901119909119909119861119861

119909119909119860119860 + 119901119901119909119909119861119861 (2)

0

minus 2000

minus 4000

minus 6000

minus 8000

minus 10000

minus 12000

minus 14000

minus 16000

minus 18000

[Nanosulfonamide] ( M)

(J)

0 50 100 150 200 250

F 1 Comparison between the experimental heats () at 300Kfor (nanosulfonamide + HSA) interactions and the calculated data(lines) via (1)

where119909119909prime119861119861 is the fraction of bound sulfonamide or nanosulfon-amide toHSA and119909119909prime119860119860 119902 119901minus119909119909prime119861119861 is the fraction of unbound sul-fonamide or nanosulfonamide We can express 119909119909119861119861 fractionsas the sulfonamide concentrations divided by the maximumconcentration of the sulfonamide or nanosulfonamide uponsaturation of all HSA as follows

119909119909119861119861 119902[sulfonamide]

[sulfonamide]max 119909119909119860119860 119902 119901 minus 119909119909119861119861 (3)

where [sulfonamide] is the concentration of sulfonamideaer every injection and [sulfonamide]max is the maximumconcentration of the sulfonamide upon saturation of all HSA119871119871119860119860 and 119871119871119861119861 are the relative contributions of unbound andbound sulfonamide in the heats of dilution in the absenceof HSA and can be calculated from the heats of dilution ofsulfonamide or nanosulfonamide in buffer 119902119902dilut as follows

119871119871119860119860 119902 119902119902dilut + 119909119909119861119861 10076531007653120597120597119902119902dilut120597120597119909119909119861119861

10076691007669 119871119871119861119861 119902 119902119902dilut minus 119909119909119860119860 10076531007653120597120597119902119902dilut120597120597119909119909119861119861

10076691007669

(4)

e heats of sulfonamide + HSA interactions 119902119902 were t-ted to (1) across the entire sulfonamide or nanosulfonamidecompositions In the tting procedure 119901119901 was changed untilthe best agreement between the experimental and calculateddata was approached (Figures 1 and 2) e high 1199031199032 value(0999) supports the method e binding parameters forsulfonamide + HSA interactions recovered from (1) werelisted in Tables 1 and 2e agreement between the calculatedand experimental results (Figures 1 and 2) gives considerablesupport to the use of (1) 120575120575120579120579119860119860 and 120575120575120579120579119861119861 values for sulfonamide +HSA interactions are positive indicating that in the low andhigh concentrations of the sulfonamide the HSA structure isstabilizedese results suggest that the antioxidant propertyof HSA increased 119901119901 119902 119901 indicates that the binding isnoncooperative

For a set of identical and independent binding sites aplot of (Δ119902119902119902119902119902max) [HSA] versus (Δ119902119902119902119902119902) [sulfon] should bea linear plot by a slope of 119901119902119892119892 and the vertical-intercept of

Journal of Chemistry 3

0

minus 1000

minus 2000

minus 3000

minus 4000

minus 5000

minus 6000

minus 7000

[Sulfonamide] ( M)

(J)

0 25 50 75 100 125 150 175 200 225 250

F 2 Comparison between the experimental heats () at 300Kfor (sulfonamide +HSA) interactions and the calculated data (lines)via (1)

T 1 Binding parameters for HAS + sulfonamide interactione interaction is both enthalpy and entropy driven but theelectrostatic interactions are more important than hydrophobicforces 119870119870119886119886 values show that sulfonamide in the second class ofbinding sites has higher affinity for binding than the rst class ofbinding sites e positive values of 120575120575120579120579119860119860 and 120575120575120579120579119861119861 indicate that theantioxidant property of HSA increased as a result of its interactionwith sulfonamide

Parameters First binding sites Second binding sites119901119901 1 1119892119892 1 4119870119870119886119886Lsdotmolminus1 22 times 106 plusmn 250 386 times 105 plusmn 750Δ119867119867kJmolminus1 minus2463 plusmn 008 minus1245 plusmn 006Δ119866119866kJmolminus1 minus3057 plusmn 008 minus3209 plusmn 011Δ119878119878kJmolminus1 Kminus1 002 plusmn 0003 006 plusmn 0005120575120575120579120579119860119860 486120575120575120579120579119861119861 476

119870119870119889119889119892119892 through which 119892119892 and 119870119870119889119889 can be obtained [15ndash19] asfollows

Δ119902119902119902119902max

[HSA] = 10076531007653Δ11990211990211990211990210076691007669 [sulfon] 1

119892119892minus119870119870119889119889119892119892 (5)

where 119892119892 is the number of binding sites 119870119870119889119889 is the dissocia-tion equilibrium constant [HSA] and [sulfon] are the con-centrations of HSA and sulfonamide or nanosulfonamiderespectively Δ119902119902 = 119902119902max minus 119902119902 119902119902 represents the heat value ata certain ligand concentration and 119902119902max represents the heatvalue upon saturation of all HSA If 119902119902 and 119902119902max are calculatedper mole of biomacromolecule then the molar enthalpy ofbinding for each binding site (Δ119867119867) will be Δ119867119867 = 119902119902max119892119892e best linear plots with the correlation coefficient value of0999 were obtained using amounts of minus2670 and minus5400 120583120583J(equal to minus2463 minus4981 kJmolminus1) for 119902119902max in the rst andsecond binding sites respectively Dividing the 119902119902max amountsof minus2463 kJmolminus1 by 119892119892 = 1 and minus4981 kJmolminus1 by 119892119892 = 4

T 2 Binding parameters for HAS + nanosulfonamide interac-tionse interaction is both enthalpy and entropy driven indicatingthat the electrostatic interactions are dominant119870119870119886119886 values show thatnanosulfonamide has high affinity for binding to HSA e positivevalue of 120575120575120579120579119860119860 indicates that the antioxidant property of HSA increasedas a result of its interaction with nanosulfonamide e negative120575120575120579120579119861119861 value proves that nanosulfonamide dampened the anti-oxidantproperty of HSA in the high concentration of nanosulfonamide

Parameters119901119901 1119892119892 1119870119870119886119886Lsdotmolminus1 36 times 106 plusmn 650Δ119867119867kJmolminus1 minus3643 plusmn 012Δ119866119866kJmolminus1 minus3763 plusmn 015Δ119878119878kJmolminus1 Kminus1 0004 plusmn 0001120575120575120579120579119860119860 265 plusmn 006120575120575120579120579119861119861 minus3814 plusmn 009

thus gives Δ119867119867 = minus2463 for the rst binding sites and Δ119867119867 =minus1245 kJmolminus1 for the second binding sites

To compare all thermodynamic parameters in metalbinding process for HSA the change in standard Gibbs freeenergy (Δ119866119866∘) should be calculated according to (6) whosevalue can be used in (7) for calculating the change in standardentropy (Δ119878119878∘) of binding process

Δ119866119866∘ = minus119877119877119877119877 119877119877119870119870119886119886 (6)

Δ119866119866∘ = Δ119867119867∘ minus 119877119877Δ119878119878∘ (7)

where 119870119870119886119886 is the association binding constant (the inverse ofthe dissociation binding constant 119870119870119889119889) e 119870119870119886119886 values areobtained as 221 times 105 plusmn 250 and 386 times 105 plusmn 250Mminus1 forthe rst and second binding sites respectively

e results show that there are two sets of binding sitesfor sulfonamidee interaction is both enthalpy and entropydriven but the electrostatic interactions are more importantthan hydrophobic forces It was found that there is 1 site inthe rst class of binding sites and 4 sites in the second class ofbinding sites119870119870119886119886 values show that sulfonamide in the secondbinding sites has higher affinity for binding than the rstbinding sites

Energy of binding (Δ119867119867 = minus3643 kJmolminus1) for nanosul-fonamide with HSA is more negative than that of sulfon-amideerefore the energetic interaction between nanosul-fonamide andHSAhas becomemore favorablee affinity ofnanosulfonamide is roughly twice of sulfonamide thereforereduces the drug dosage frequency treatment time and sideeffects 119870119870119886119886 values show that nanosulfonamide has higheraffinity for binding with HSA than sulfonamide e moreeffectiveness of nanosulfonamide can be attributed to itssmall size which result in reducing drug toxicity controllingtime release of the drug and modication of drug pharma-cokinetics and biological distribution e positive 120575120575120579120579119860119860 value(Table 2) shows that nanosulfonamide (in around 30 120583120583M ofnanosulfonamide) stabilizes HSA structure and increases theanti-oxidant property ofHSAenegative 120575120575120579120579119861119861 value indicates


that nanosulfonamide dampened the anti-oxidant propertyof HSA in the high concentration domain (around 250 120583120583Mofnanosulfonamide)

onct of nterests

ere is no conict of interest for any authors with ermo-metric Digitam 3 soware

Acknowledgment

e nancial support of Imam Khomeini International Uni-versity is gratefully acknowledged

References

[1] T A Waldmann ldquoAlbumin cataboiismrdquo in Albumin StructureFunction and Uses V M Rosenoer M Oratz and M ARothschild Eds pp 255ndash273 Pergamon Oxford UK 1977

[2] E Bourdon and D Blache ldquoe importance of proteins indefense against oxidationrdquo Antioxidants and Redox Signalingvol 3 no 2 pp 293ndash311 2001

[3] T J PetersAll aboutAlbumin Academic Press SanDiego CalifUSA 1996

[4] H Watanabe U Kragh-Hansen S Tanase et al ldquoConfor-mational stability and warfarin-binding properties of humanserum albumin studied by recombinant mutantsrdquo BiochemicalJournal vol 357 no 1 pp 269ndash274 2001

[5] W J Long and J W Henderson ldquoAnalysis of sulfa drugs oneclipse plus C18rdquo 5989-5436EN 2006

[6] A Goumlbel A omsen C S McArdell et al ldquoExtraction anddetermination of sulfonamides macrolides and trimethoprimin sewage sludgerdquo Journal of Chromatography A vol 1085 no2 pp 179ndash189 2005

[7] S A Tilles ldquoPractical issues in the management of hypersen-sitivity reactions sulfonamidesrdquo Southern Medical Journal vol94 no 8 pp 817ndash824 2001

[8] W E Mueller and U Wollert ldquoCircular dichroism studies onthe interaction of four structurally related long acting sulfon-amides with human and bovine serum albuminrdquo BiochemicalPharmacology vol 25 no 13 pp 1459ndash1464 1976

[9] G Rezaei Behbehani A A Saboury E Poorakbar and LBarzegar ldquoApplication of the extended solvation model forthermodynamic study of copper ion binding to Jack beanureaserdquo Journal of ermal Analysis and Calorimetry vol 102no 3 pp 1141ndash1146 2010

[10] G R Behbehani A A Saboury and E Yahaghi ldquoA ther-modynamic study of nickel ion interaction with bovine car-bonic anhydrase II moleculerdquo Journal of ermal Analysis andCalorimetry vol 100 no 1 pp 283ndash288 2010

[11] G Rezaei Behbehani A A Saboury and F Sabbaghy ldquoAcalorimetric study on the interaction of zinc and cadmium ionswith Jack bean ureaserdquoChinese Journal of Chemistry vol 29 no3 pp 446ndash450 2011

[12] G Rezaei Behbehani A Divsalar A A Saboury F Faridbodand M R Ganjali ldquoA thermodynamic study on the binding ofhuman serum albumin with lanthanum ionrdquo Chinese Journal ofChemistry vol 28 no 2 pp 159ndash163 2010

[13] L Barzegar G Rezaei Behbehani and A A Saboury ldquoAthermodynamic study of zinc ion interaction with bovine

carbonic anhydrase II at different temperaturesrdquo Journal ofSolution Chemistry vol 40 no 5 pp 843ndash848 2011

[14] G Rezaei Behbehani A A Saboury L Barzegar O ZareanJ Abedini and M Payehghdr ldquoA thermodynamic study onthe interaction of nickel ion with myelin basic protein byisothermal titration calorimetryrdquo Journal of ermal Analysisand Calorimetry vol 101 no 1 pp 379ndash384 2010

[15] G Rezaei Behbehani A A Saboury O Zarean L Barzegar andS Ghamamy ldquoermodynamic study of myelin basic proteinupon interaction with [Hg2+] using extension solvation modelrdquoChinese Journal of Chemistry vol 28 no 5 pp 713ndash718 2010

[16] A A Saboury M S Atri M H Sanati and M SadeghildquoApplication of a simple calorimetric data analysis on thebinding study of calcium ions by human growth hormonerdquoJournal of ermal Analysis and Calorimetry vol 83 no 1 pp175ndash179 2006

[17] G Rezaei Behbehani A A Saboury S Tahmasebi SarvestaniM Mohebbian M Payehghadr and J Abedini ldquoA thermody-namic study on the binding of theophylline with human serumalbuminrdquo Journal ofermal Analysis and Calorimetry vol 102no 2 pp 793ndash798 2010

[18] E Tazikeh G Rezaei-Behbehani A A Saboury et al ldquoer-modynamic study of the binding of mercury ion to humangrowth hormone at different temperaturesrdquo Journal of SolutionChemistry vol 40 no 4 pp 575ndash586 2011

[19] A A Saboury M S Atri M H Sanati A A Moosavi-Movahedi G H Hakimelahi and M Sadeghi ldquoA thermo-dynamic study on the interaction between magnesium ionand human growth hormonerdquo Biopolymers vol 81 no 2 pp120ndash126 2006

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Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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SpectroscopyInternational Journal of


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Applied ChemistryJournal of



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Spectroscopy

Analytical ChemistryInternational Journal of


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Quantum Chemistry


Organic Chemistry International

ElectrochemistryInternational Journal of



CatalystsJournal of


their effects on the stability and the structural changes of theHSA molecules

2 Materials andMethod

Human serum albumin (HSAMW= 66411 grmol) and Trisbuffer used were of analytical grade with the highest purityavailable without any purication Sulfonamide derivative(N-phenyl benzene sulfonyl hydrazide) was synthesizede isothermal titrationmicrocalorimetric experiments wereperformed with the four-channel commercial microcalori-metric system Sulfonamide and nanosulfonamide solutions(16129 120583120583M) were injected by the use of a Hamilton syringeinto the calorimetric titration vessel which contained 18mLHSA (6022 120583120583M) Injection of sulfonamide solution intothe perfusion vessel was repeated 29 times with 10120583120583Lper injection e calorimetric signal was measured by adigital voltmeter that was part of a computerized recordingsystem e heats of each injection was calculated by theldquoermometric Digitam 3rdquo soware program e heat ofdilution of the sulfonamide and nanosulfonamide solutionswere measured as described above except HSA was excludede microcalorimeter was frequently calibrated electricallyduring the course of the study

3 Results and Discussion

We have shown previously that the heats of the ligand +HSA interactions in the aqueous solvent mixtures can becalculated via the following equation [9ndash14]

119902119902 119902 119902119902max119909119909prime119861119861 minus 120575120575

120579120579119860119860 10076511007651119909119909

prime119860119860119871119871119860119860 + 119909119909

prime11986111986111987111987111986111986110076671007667

minus 10076501007650120575120575120579120579119861119861 minus 12057512057512057912057911986011986010076661007666 10076511007651119909119909

prime119860119860119871119871119860119860 + 119909119909

prime11986111986111987111987111986111986110076671007667 119909119909

prime119861119861

(1)

where 119902119902 are the heats of sulfonamide + HSA or nanosulfon-amide +HSA interactions and 119902119902max represents the heat valueupon saturation of all HSA e parameters 120575120575120579120579119860119860 and 120575120575120579120579119861119861 arethe indexes of HSA stability in the low and high sulfonamideconcentrations respectively Cooperative binding requiresthat themacromolecule hasmore than one binding site sincecooperativity results from the interactions between identicalbinding sites with the same ligand If the binding of a ligandat one site increases the affinity for that ligand at anothersite then the macromolecule exhibits positive cooperativityConversely if the binding of a ligand at one site lowersthe affinity for that ligand at another site then the enzymeexhibits negative cooperativity If the ligand binds at each siteindependently then the binding is noncooperative 119901119901 119901 119901or 119901119901 119901 119901 indicate positive or negative cooperativity of amacromolecule for binding with a ligand respectively 119901119901 119902119901 indicates that the binding is noncooperative 119909119909prime119861119861 can beexpressed as follows

119909119909prime119861119861 119902119901119901119909119909119861119861

119909119909119860119860 + 119901119901119909119909119861119861 (2)

0

minus 2000

minus 4000

minus 6000

minus 8000

minus 10000

minus 12000

minus 14000

minus 16000

minus 18000

[Nanosulfonamide] ( M)

(J)

0 50 100 150 200 250

F 1 Comparison between the experimental heats () at 300Kfor (nanosulfonamide + HSA) interactions and the calculated data(lines) via (1)

where119909119909prime119861119861 is the fraction of bound sulfonamide or nanosulfon-amide toHSA and119909119909prime119860119860 119902 119901minus119909119909prime119861119861 is the fraction of unbound sul-fonamide or nanosulfonamide We can express 119909119909119861119861 fractionsas the sulfonamide concentrations divided by the maximumconcentration of the sulfonamide or nanosulfonamide uponsaturation of all HSA as follows

119909119909119861119861 119902[sulfonamide]

[sulfonamide]max 119909119909119860119860 119902 119901 minus 119909119909119861119861 (3)

where [sulfonamide] is the concentration of sulfonamideaer every injection and [sulfonamide]max is the maximumconcentration of the sulfonamide upon saturation of all HSA119871119871119860119860 and 119871119871119861119861 are the relative contributions of unbound andbound sulfonamide in the heats of dilution in the absenceof HSA and can be calculated from the heats of dilution ofsulfonamide or nanosulfonamide in buffer 119902119902dilut as follows

119871119871119860119860 119902 119902119902dilut + 119909119909119861119861 10076531007653120597120597119902119902dilut120597120597119909119909119861119861

10076691007669 119871119871119861119861 119902 119902119902dilut minus 119909119909119860119860 10076531007653120597120597119902119902dilut120597120597119909119909119861119861

10076691007669

(4)

e heats of sulfonamide + HSA interactions 119902119902 were t-ted to (1) across the entire sulfonamide or nanosulfonamidecompositions In the tting procedure 119901119901 was changed untilthe best agreement between the experimental and calculateddata was approached (Figures 1 and 2) e high 1199031199032 value(0999) supports the method e binding parameters forsulfonamide + HSA interactions recovered from (1) werelisted in Tables 1 and 2e agreement between the calculatedand experimental results (Figures 1 and 2) gives considerablesupport to the use of (1) 120575120575120579120579119860119860 and 120575120575120579120579119861119861 values for sulfonamide +HSA interactions are positive indicating that in the low andhigh concentrations of the sulfonamide the HSA structure isstabilizedese results suggest that the antioxidant propertyof HSA increased 119901119901 119902 119901 indicates that the binding isnoncooperative

For a set of identical and independent binding sites aplot of (Δ119902119902119902119902119902max) [HSA] versus (Δ119902119902119902119902119902) [sulfon] should bea linear plot by a slope of 119901119902119892119892 and the vertical-intercept of


0

minus 1000

minus 2000

minus 3000

minus 4000

minus 5000

minus 6000

minus 7000

[Sulfonamide] ( M)

(J)

0 25 50 75 100 125 150 175 200 225 250





Δ119902119902119902119902max

[HSA] = 10076531007653Δ11990211990211990211990210076691007669 [sulfon] 1

119892119892minus119870119870119889119889119892119892 (5)






Δ119866119866∘ = minus119877119877119877119877 119877119877119870119870119886119886 (6)

Δ119866119866∘ = Δ119867119867∘ minus 119877119877Δ119878119878∘ (7)






onct of nterests


Acknowledgment


References






























Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of


0

minus 1000

minus 2000

minus 3000

minus 4000

minus 5000

minus 6000

minus 7000

[Sulfonamide] ( M)

(J)

0 25 50 75 100 125 150 175 200 225 250





Δ119902119902119902119902max

[HSA] = 10076531007653Δ11990211990211990211990210076691007669 [sulfon] 1

119892119892minus119870119870119889119889119892119892 (5)






Δ119866119866∘ = minus119877119877119877119877 119877119877119870119870119886119886 (6)

Δ119866119866∘ = Δ119867119867∘ minus 119877119877Δ119878119878∘ (7)






onct of nterests


Acknowledgment


References






























Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of



onct of nterests


Acknowledgment


References






























Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of










Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of

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