In vitro influence of fatty acids and bilirubin on binding of mycophenolic acid to human serum albumin

Human serum albumin (HSA) is the most abundant human plasma protein. HSA plays a crucial role in many binding endos- and exogenous substances, which affects their pharmacological effect. The innovative aspect of the study is not only the interaction of fatted (HSA) and defatted (dHSA) human serum albumin with ibuprofen (IBU), but the analysis of the influence of temperature on the structural modifications of albumin and the interaction between the drug and proteins from the temperature characteristic of near hypothermia (308 K) to the temperature reflecting inflammation in the body (312 K and 314 K). Ibuprofen is a non-steroidal anti-inflammatory drug. IBU is used to relieve acute pain, inflammation, and fever. To determine ibuprofen’s binding site in the tertiary structure of HSA and dHSA, fluorescence spectroscopy was used. On its basis, the fluorescent emissive spectra of albumin (5 × 10−6 mol/dm3) without and with the presence of ibuprofen (1 × 10−5–1 × 10−4 mol/dm3) was recorded. The IBU-HSA complex’s fluorescence was excited by radiation of wavelengths of λex 275 nm and λex 295 nm. Spectrophotometric spectroscopy allowed for recording the absorbance spectra (zero-order and second derivative absorption spectra) of HSA and dHSA under the influence of ibuprofen (1 × 10−4 mol/dm3). To characterize the changes of albumin structure the presence of IBU, circular dichroism was used. The data obtained show that the presence of fatty acids and human serum albumin temperature influences the strength and type of interaction between serum albumin and drug. Ibuprofen binds more strongly to defatted human serum albumin than to albumin in the presence of fatty acids. Additionally, stronger complexes are formed with increasing temperatures. The competitive binding of ibuprofen and fatty acids to albumin may influence the concentration of free drug fraction and thus its therapeutic effect.

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Synthesis and In Vitro Assessment of pH-Sensitive Human Serum Albumin Conjugates of Pirarubicin

Pharmaceuticals ◽

10.3390/ph14010022 ◽

2020 ◽

Vol 14 (1) ◽

pp. 22

Author(s):

Kenji Tsukigawa ◽

Shuhei Imoto ◽

Keishi Yamasaki ◽

Koji Nishi ◽

Toshihiko Tsutsumi ◽

...

Keyword(s):

Human Serum Albumin ◽

Serum Albumin ◽

Human Serum ◽

Coupling Reaction ◽

Synthetic Polymer ◽

Ph Sensitive ◽

Acidic Ph ◽

Polymer Conjugate ◽

Acidic Conditions

In a previous study, we reported on the development of a synthetic polymer conjugate of pirarubicin (THP) that was formed via an acid-labile hydrazone bond between the polymer and the THP. However, the synthetic polymer itself was non-biodegradable, which could lead to unexpected adverse effects. Human serum albumin (HSA), which has a high biocompatibility and good biodegradability, is also a potent carrier for delivering antitumor drugs. The objective of this study was to develop pH-sensitive HSA conjugates of THP (HSA-THP), and investigate the release of THP and the cytotoxicity under acidic conditions in vitro for further clinical development. HSA-THP was synthesized by conjugating maleimide hydrazone derivatives of THP with poly-thiolated HSA using 2-iminothiolane, via a thiol-maleimide coupling reaction. We synthesized two types of HSA-THP that contained different amounts of THP (HSA-THP2 and HSA-THP4). Free THP was released from both of the HSA conjugates more rapidly at an acidic pH, and the rates of release for HSA-THP2 and HSA-THP4 were similar. Moreover, both HSA-THPs exhibited a higher cytotoxicity at acidic pH than at neutral pH, which is consistent with the effective liberation of free THP under acidic conditions. These findings suggest that these types of HSA-THPs are promising candidates for further development.

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Generation of fatty acids from 1,2-dipalmitoyl-sn-glycero-3-phosphocholine/cardiolipin liposomes that stabilize recombinant human serum albumin

Journal of Liposome Research ◽

10.3109/08982104.2012.747535 ◽

2013 ◽

Vol 23 (2) ◽

pp. 101-109 ◽

Cited By ~ 1

Author(s):

Grant E. Frahm ◽

Brooke E. Cameron ◽

Jeffrey C. Smith ◽

Michael J. W. Johnston

Keyword(s):

Fatty Acids ◽

Human Serum Albumin ◽

Serum Albumin ◽

Human Serum ◽

Recombinant Human Serum Albumin

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The in Vitro Anti-HIV Efficacy of Negatively Charged Human Serum Albumin Is Antagonized by Heparin

AIDS Research and Human Retroviruses ◽

10.1089/aid.1997.13.677 ◽

1997 ◽

Vol 13 (8) ◽

pp. 677-683 ◽

Cited By ~ 3

Author(s):

P.J. SWART ◽

C.S. SUN ◽

M.E. KUIPERS ◽

C. ASUNCION ◽

S. JOSEPHS ◽

...

Keyword(s):

Human Serum Albumin ◽

Serum Albumin ◽

Human Serum ◽

Anti Hiv

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Kinetic study of the photochemical changes of (ZZ)-bilirubin IX α bound to human serum albumin. Demonstration of (EZ)-bilirubin IX α as an intermediate in photochemical changes from (ZZ)-bilirubin IX α to (EZ)-cyclobilirubin IX α

Biochemical Journal ◽

10.1042/bj2260251 ◽

1985 ◽

Vol 226 (1) ◽

pp. 251-258 ◽

Cited By ~ 25

Author(s):

S Itoh ◽

S Onishi

Keyword(s):

Human Serum Albumin ◽

Serum Albumin ◽

Kinetic Study ◽

Human Serum ◽

Photochemical Reaction ◽

Relative Rate ◽

Significant Preference ◽

Geometrical Isomers ◽

Relative Rate Constants

The present study was performed to elucidate why the photochemical reaction of (ZZ)-bilirubin bound to human serum albumin is singularly selective, and only one of the two (EZ)- and (ZE)-bilirubins, the (ZE)-isomer, is produced. In a kinetic study of the photochemical reaction in vitro, the sum of the relative rate constants of photochemical transformation of (EZ)-bilirubin into both (EZ)-cyclobilirubin and (ZZ)-bilirubin, with a significant preference for the former, was proved to be considerably larger than that of the transformation of (ZZ)-bilirubin into (EZ)-bilirubin. Therefore only one of the geometrical isomers, namely (ZE)-bilirubin, is apparently formed. It was concluded that (EZ)-bilirubin photochemically undergoes (EZ)-cyclization, i.e. structural photoisomerization, while bound to its high-affinity site on human serum albumin, and is an intermediate in the transformation of (ZZ)-bilirubin into (EZ)-cyclobilirubin.

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