Different rates of formation of secondary and tertiary structure during renaturation of urea-denatured human serum albumin

1989 ◽  
Vol 54 (9) ◽  
pp. 2542-2549 ◽  
Author(s):  
Josef Chmelík

A comparison of the results of our polarimetric measurements with the polarographic experiments reported earlier shows that the restoration of the secondary structure during the renaturation of human serum albumin is a process which is faster than the formation of the tertiary structure. These results, which are in agreement with the data on the kinetic control of protein folding, are discussed from the viewpoint of the importance of the individual types of interactions which take place during the formation and stabilization of three-dimensional protein structures. We have been able to demonstrate the great importance of electrostatic and hydrophobic interactions which together with the disulfide bonds are essential for the reversibility of the denaturation phenomena. The discussion also shows the essential role which evolution processes play in the selection of the mode of protein folding.

1988 ◽  
Vol 53 (2) ◽  
pp. 411-422 ◽  
Author(s):  
Josef Chmelík ◽  
Pavel Anzenbacher ◽  
Jitka Chmelíková ◽  
Milada Matějčková ◽  
Vítěz Kalous

The mechanism of denaturation of human serum albumin by urea was examined by polarography, polarimetry, circular dichroism, UV-spectrophotometry, gel chromatography, and polyacrylamide gel electrophoresis. Comparison of the results obtained by these methods shows that this reaction is a complex process which cannot be described by a two-state denaturation model. It has been demonstrated that the different states which denaturation produces arise under different denaturation conditions. The different behavior of various species of human serum albumin (monomer, mercaptalbumin and nonmercaptalbumin) during denaturation by urea was examined. As a result the following probable denaturation scheme was proposed: The denaturation of human serum albumin by urea is regarded as a stepwise process involving one stable intermediary product at least ( demonstrated electrophoretically). After the rapid initial change of the ordered helical structure extensive hydrophobic domains of the molecule remain folded. Cystine residues are gradually liberated from these domains. Denaturated mercaptalbumin has the conformation of a random coil in which the pairing of native disulfide bonds has been altered because of SH-S-S interchange reactions; in contrast native disulfide bonds are retained in nonmercaptalbumin.


2021 ◽  
Vol 89 (3) ◽  
pp. 30
Author(s):  
Anna Ploch-Jankowska ◽  
Danuta Pentak ◽  
Jacek E. Nycz

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.


Science ◽  
1989 ◽  
Vol 244 (4909) ◽  
pp. 1195-1198 ◽  
Author(s):  
D. Carter ◽  
X. He ◽  
S. Munson ◽  
P. Twigg ◽  
K. Gernert ◽  
...  

2018 ◽  
Vol 54 (82) ◽  
pp. 11586-11589
Author(s):  
Jeong Yu Lee ◽  
Ho Yeon Son ◽  
Jae Chul Park ◽  
Jongnam Park ◽  
Yoon Sung Nam

Self-assembly of monodisperse superparamagnetic iron oxide nanocrystals into a close-packed, three-dimensional (3D) superlattice is designed within cross-linked protein-based nanoparticles composed of human serum albumin and polyethylene glycol.


2006 ◽  
Vol 10 (01) ◽  
pp. 33-42 ◽  
Author(s):  
Myriam E. Rodriguez ◽  
Daniel A. Fernández ◽  
Josefina Awruch ◽  
Silvia E. Braslavsky ◽  
Lelia E. Dicelio

The photophysical properties of tetrakis(1,1-dimethyl-2-trimethylammonium)ethylphthalocyaninato zinc(II) tetraiodide (I) – a water-soluble cationic phthalocyanine – are presented in the presence of human serum albumin (HSA) and in micelles of sodium dodecylsulfate ( SDS ) and hexadecyltrimethylammonium chloride ( CTAC ). Spectrophotometric measurements showed that the surfactants SDS and CTAC induce monomerization of I, although the latter less efficiently than the former. This effect is less pronounced in the presence of HSA. The strength of this effect is evaluated through dimerization constants, which are Kd = (5 ± 1) × 105 m−1 in SDS , (1.5 ± 0.5) × 106 M −1 in CTAC , and (1.8 ± 0.9) × 106 M −1 in HSA. Fluorescence experiments confirm that aggregation of I drops as the concentration of surfactant is raised. Triplet quantum yields also decreased upon aggregation and were Φ T = 0.59, 0.16, and < 0.01 in SDS , CTAC , and HSA, respectively. These results indicate that the affinity of I for the environment is not just due to ionic interactions; hydrophobic interactions play an equally important role.


2010 ◽  
Vol 24 (5) ◽  
pp. 547-557 ◽  
Author(s):  
Xu Chen ◽  
Jia-Ming Ma ◽  
Ke-Lan Yong ◽  
Jing-Ci Lv ◽  
Xia-Bing Zhang

The interaction between loureirin B (Lour B) and human serum albumin (HSA) was investigated by fluorescence and UV–vis absorption spectroscopy. Experimental results indicated that loureirin B had a strong ability to quench the intrinsic fluorescence of HSA through a dynamic quenching procedure. The fluorescence quenching data revealed that the quenching constants (KSV) 2.68×104, 3.30×104and 4.10×104l/mol at 300, 310 and 320 K, respectively. Based on the thermodynamic parameters obtained, the positive values of enthalpy change ΔH and entropy change ΔS suggested that hydrophobic forces played a major role in the interaction of Lour B with HSA. According to Förster theory of energy transfer, the distancerbetween HSA and Lour B was calculated to be 2.85 nm. Furthermore, the effect of Lour B on the conformation of HSA was analyzed by synchronous fluorescence and three-dimensional fluorescence spectra.


2015 ◽  
Vol 4 (1) ◽  
pp. 77-83 ◽  
Author(s):  
A. Henseleit ◽  
C. Pohl ◽  
Th. Bley ◽  
E. Boschke

Abstract. Continuously monitoring cell cultures is essential for both controlling critical parameters and improving understanding of key processes. An ideal technique in this context is surface plasmon resonance (SPR) spectroscopy, which essentially exploits changes in the angle of incident light that occur when molecules bind to a surface. It provides the ability to monitor real-time changes in small concentrations of various molecules, with no need for additional labels or sample preparation. Here we present an SPR-based immunoassay for monitoring concentrations of human serum albumin (HSA), and compare its sensitivity when used in conjunction with a Biacore platform and the cheaper, smaller liSPR system. In conjunction with either system, the immunoassay can detect HSA (a hepatocyte viability marker) at concentrations typically present in three-dimensional hepatocyte cultures mimicking the liver used to evaluate effects of drug candidates before exposure to humans or animals. Furthermore, in conjunction with the liSPR system, it is sufficiently sensitive to measure the much lower HSA levels present in skin–hepatocyte co-cultures.


Sign in / Sign up

Export Citation Format

Share Document