Human Serum Albumin Binding of Novel Antiretroviral Nucleoside Derivatives of AZT

Quevedo, Mario Alfredo; Moroni, Guillermo N.; Briñón, Margarita C.

doi:10.1006/bbrc.2001.5878

Cited by 25 publications

(13 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Among proteins, serum albumin is the principal extracellular protein of the circulatory system that has been extensively studied. It functions as a physiological carrier for numerous endogenous and exogenous compounds such as fatty acids, amino acids, steroids, metal ions, and drugs [9][10][11]. Human serum albumin (HSA) is a single chain 66 kDa non-glycosylated α-helical polypeptide.…”

Section: Introductionmentioning

confidence: 99%

Biophysical Interactions of Novel Oleic Acid Conjugate and its Anticancer Potential in HeLa Cells

et al. 2015

View full text Add to dashboard Cite

Novel conjugate 2,6-Diisopropylphenol-Oleic acid (2,6P-OLA) has shown potent anticancer activity on various cancer cell lines (Khan et al. Lipids 47:973-986, 2012). In the present study, the protein-or/ and DNA-binding property of 2,6P-OLA was evaluated that could predict its potential toxic effect, in vitro. Preferential structural stability and interaction mechanism of 2,6P-OLA to human serum albumin (HSA) and calf thymus DNA (CT-DNA) was used as model molecules, employing fluorescence spectroscopy (FS) and circular dichroism (CD) methods. The binding and apoptotic activities of conjugate were determined on bacterial recombinant DNA, pBR322 and human cancer cell line, HeLa, respectively. FS studies showed a strong conjugate binding affinity to HSA with overall binding constant of K = 7.66 (±0.03) × 10(2) M(-1). Higher concentration induced detectable changes in the CD spectrum of HSA. The conjugate complexation altered HSA secondary conformation by an increase in α-helices and decrease in β-sheets. Flourescence quenching studies with CT-DNA exhibited K = 1.215 × 10(2) L mol(-1) where 2,6P-OLA efficiently displaced the ethidium bromide (EtBr) bound DNA indicating its strong competition with EtBr for intercalation. Similarly, 2,6P-OLA was able to partially bind pBR322, resulting in decrease the intensity of EtBr gradually. The conjugate significantly reduced survival of HeLa cells. Morphological studies revealed altered cell morphology, suggesting apoptotic death of HeLa cells. Overall, our data shows that 2,6P-OLA bind well with both HSA and DNA and possessed anticancer activities.

show abstract

Section: Introductionmentioning

confidence: 99%

Biophysical Interactions of Novel Oleic Acid Conjugate and its Anticancer Potential in HeLa Cells

et al. 2015

View full text Add to dashboard Cite

show abstract

“…The work presented in this article attempts to confirm and extend these data with a more complete examination of liver preparations and buffer conditions to identify the factors affecting enzyme behavior in HLMs that cause underprediction of in vivo clearance. AZT is an ideal substrate to work with because it is cleared almost completely via hepatic metabolism (PDR, 2002), it is not appreciably bound in plasma or liver tissue (Hardman et al, 2001;Quevedo et al, 2001), and its clearance is mediated by just one enzyme in humans (Court et al, 2003). Large differences exist in kinetic parameters for AZT between HLMs and hepatocytes that affect the predicted clearance.…”

Section: Discussionmentioning

confidence: 99%

Altered Azt (3′-Azido-3′-Deoxythymidine) Glucuronidation Kinetics in Liver Microsomes as an Explanation for Underprediction of in Vivo Clearance: Comparison to Hepatocytes and Effect of Incubation Environment

Engtrakul¹,

Foti²,

Strelevitz³

et al. 2005

Drug Metab Dispos

View full text Add to dashboard Cite

ABSTRACT:Human liver microsomes are a reagent commonly used to predict human hepatic clearance of new chemical entities via phase 1 metabolism. Another common metabolic pathway, glucuronidation, can also be observed in human liver microsomes, although the scalability of this process has not been validated. In fact, several groups have demonstrated that clearance estimated from liver microsomes with UDP-glucuronic acid typically underpredicts the actual in vivo clearance more than 10-fold for compounds that are predominantly glucuronidated. In contrast, clearance predicted using human hepatocytes, for these same compounds, provides a more accurate assessment of in vivo clearance. We sought to characterize the kinetics of glucuronidation of the selective UGT2B7 substrate AZT (3-azido-3-deoxythymidine), a selective UGT2B7 substrate, in human liver microsomes (HLMs), recombinant UGT2B7, and human hepatocytes. Apparent K m values in these three preparations were 760, 490, and 87 M, with apparent V max values highest in hepatocytes. The IC 50 for ibuprofen against AZT glucuronidation, when run at its K m concentration in HLMs and hepatocytes, was 975 and 170 M, respectively. Since incubation conditions have been shown to modulate glucuronidation rates, AZT glucuronidation was performed in various physiological and nonphysiological buffer systems, namely Tris, phosphate, sulfate, carbonate, acetate, human plasma, deproteinized human liver cytosol, and Williams E medium. The data showed that carbonate and Williams E medium, more physiologically relevant buffers, yielded the highest rates of AZT glucuronidation. K m observed in HLM/carbonate was 240 M, closer to that found in hepatocytes, suggesting that matrix differences might cause the kinetic differences observed between liver preparations. Caution should be exercised when extrapolating metabolic lability via glucuronidation or inhibition of UGT enzymes from human liver microsomes, since this system appears to underpredict the degree of lability or inhibition, respectively, due in part to an apparent decrease in substrate affinity.

show abstract

“…The AZT binding to plasma proteins, especially albumin, controls the concentration of the free drug, and hence affects the drug's pharmacokinetics, storage, toxicity, transportability to the tissue and through cell membranes. It is known that AZT exhibits poor binding to human serum albumin (HSA) (Quevedo et al, 2001). Such characteristic was believed to be one of the main reasons for its short half-life time (Luzier and Morse, 1993;Quevedo et al, 2001).…”

Section: Introductionmentioning

confidence: 99%

“…It is known that AZT exhibits poor binding to human serum albumin (HSA) (Quevedo et al, 2001). Such characteristic was believed to be one of the main reasons for its short half-life time (Luzier and Morse, 1993;Quevedo et al, 2001). However, the structure basis of such characteristic has not been reported in details.…”

Section: Introductionmentioning

confidence: 99%

A new drug binding subsite on human serum albumin and drug–drug interaction studied by X-ray crystallography

Zhu

Yang

Chen

et al. 2008

Journal of Structural Biology

121

View full text Add to dashboard Cite

Human Serum Albumin Binding of Novel Antiretroviral Nucleoside Derivatives of AZT

Cited by 25 publications

References 16 publications

Biophysical Interactions of Novel Oleic Acid Conjugate and its Anticancer Potential in HeLa Cells

Biophysical Interactions of Novel Oleic Acid Conjugate and its Anticancer Potential in HeLa Cells

Altered Azt (3′-Azido-3′-Deoxythymidine) Glucuronidation Kinetics in Liver Microsomes as an Explanation for Underprediction of in Vivo Clearance: Comparison to Hepatocytes and Effect of Incubation Environment

A new drug binding subsite on human serum albumin and drug–drug interaction studied by X-ray crystallography

Contact Info

Product

Resources

About