Time-dependent conformational changes in adsorbed albumin and its effect on platelet adhesion

Citation

Sivaraman, Balakrishnan & Latour, Robert A. (2012). Time-dependent conformational changes in adsorbed albumin and its effect on platelet adhesion. Langmuir: the ACS journal of surfaces and colloids, 28(5), 2745-2752.

Abstract

Recent studies have shown that platelets can adhere to adsorbed albumin (Alb) through a receptor-mediated mechanism, but only if the Alb undergoes more than a critical degree of adsorption-induced unfolding. The objectives of this research were to investigate whether Alb that was initially adsorbed in a manner that induced unfolding that was less than this critical level would undergo further unfolding with time and, if so, whether this would induce the onset of platelet adhesion once this critical level was exceeded. To address these questions, CD spectropolarimetry was used to monitor the structure of Alb on OH- and CH(3)-functionalized alkanethiol self-assembled monolayer surfaces, with the Alb initially adsorbed under conditions resulting in degrees of unfolding that were below this critical level, and then the adsorbed Alb layers were aged over 6 months in sterile physiological saline at 37 °C. Platelet adhesion to Alb was quantified at selected time points via a lactate dehydrogenase (LDH) assay. The results indicate that an adsorbed Alb layer does undergo further structural changes with increasing residence time and supports platelet adhesion once it unfolds beyond the previously determined critical level. These results may be relevant to the clinically observed problem of the onset of late-thrombosis, which occurs on cardiovascular implants such as drug-eluting stents.

Keyword(s)

Adsorption
Albumins
Blood Platelets
Humans
Protein Conformation
Surface Properties
Time Factors

Reference Type

Journal Article

Secondary Title

Langmuir: the ACS journal of surfaces and colloids

Author(s)

Sivaraman, Balakrishnan
Latour, Robert A.

Year Published

2012

Date Published

1328572800

Volume Number

28

Issue Number

5

Pages

2745-2752

ISSN/ISBN

1520-5827

DOI

10.1021/la204777x