Selective adsorption of serum proteins by chrysotile and crocidolite

Our plain-English summary of Selective adsorption of serum proteins by chrysotile and crocidolite, by F. Valerio, D. Balducci, L. Scarabelli (Environmental Research, 1986).

The study

• Authors: F. Valerio, D. Balducci, L. Scarabelli
• Journal: Environmental Research
• Published: 1986;41(2):432-9
• Cited by: 11 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Two distinct and contemporaneous adsorption mechanisms occur when serum proteins are incubated with chrysotile and crocidolite. The first one appears to be reversible and nonspecific, independent of the characteristics of the protein and the fiber surface. The second process seems to depend on fiber type and to involve only some protein species that are strongly concentrated on the fiber surface. This latter adsorption mechanism appears to be electrostatic in nature.

In plain English

This was a laboratory experiment on fibers and serum, not a study of people. The authors added 20 mg of chrysotile or crocidolite fibers (UICC reference standards) to a buffer solution, added fetal calf serum, and incubated the mix for 1 hour at 37°C. They measured how much protein the fibers took up. They then washed the fibers with buffer and then with a detergent (SDS), and sorted the released proteins by size. Measured as human albumin, adsorption was 0.145 micromoles per gram for chrysotile and 0.054 for crocidolite. Proteins washed off by buffer were mainly albumin and looked similar for both fibers and for a control filter. Proteins released by SDS differed greatly from the serum pattern, with high concentrations of small and large proteins on both fibers, especially crocidolite. The authors concluded that proteins may attach by at least two mechanisms, one reversible and nonspecific, the other probably electrostatic. They suggested that fiber size may be necessary but not sufficient for asbestos to cause cancer. They described their gel measurements as semiquantitative.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Laboratory (in vitro) experiment: asbestos fibers incubated with serum, then proteins eluted from the fibers and separated by gel electrophoresis
• Who was studied: No human or animal subjects; proteins from fetal calf serum, tested with reference samples of chrysotile and crocidolite fibers
• Exposure: 20 mg of UICC chrysotile or crocidolite fibers in 30 ml phosphate buffer, incubated with fetal calf serum for 1 hour at 37°C
• Main results:
  • Specific adsorption of serum proteins (calculated as human albumin) was 0.145 micromoles per gram for chrysotile and 0.054 micromoles per gram for crocidolite (printed as 'txmol/g' in the scan).
  • Washing the fibers with buffer released some adsorbed proteins. The main component had a molecular weight of about 60,000, corresponding to albumin.
  • The patterns of proteins released by buffer were very similar for chrysotile and crocidolite.
  • The same buffer-wash results, with lower optical density, were obtained from the control filter without fibers.
  • No appreciable protein was found in the SDS solution from the control filter.
  • SDS released other proteins from the fibers, in a pattern very different from serum. Low (15,000-11,000) and high (80,000-190,000) molecular weight proteins were highly concentrated on both fibers, especially crocidolite.
  • The authors interpreted the different buffer and SDS patterns as showing that serum proteins may be adsorbed by at least two different mechanisms.
  • The authors described the first mechanism as reversible and nonspecific.
  • The authors described the second mechanism as probably electrostatic, involving charges on the fiber and on the proteins.
• The authors' conclusion: The authors concluded that fiber dimensions may be a necessary but not sufficient condition for asbestos and other inorganic particles to induce cancer, and that a specific adsorption characteristic may be one of the other conditions.
• Limitations the authors state:
  • The authors stated that the optical density measurements of gel bands gave only semiquantitative indications of the relative amounts of proteins.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Chrysotile, Crocidolite.

Medical terms in this study, explained in our Lexicon: Chrysotile, Crocidolite.

Related studies

• Adsorption of proteins by chrysotile and crocidolite: role of molecular weight and charge density — F. Valerio, D. Balducci, et al. (1987)
• The adsorption of biological macromolecules by mineral dusts — R. Desai, R.J. Richards (1978)
• Silica binds serum proteins resulting in a shift of the dose-response for silica-induced chemokine expression in an alveolar type II cell line — E.G. Barrett, C. Johnston, et al. (1999)
• Serum protein concentrations and respiratory tract abnormalities following short-term exposure to amosite: a comparison between former asbestos workers and unexposed controls — D.R. Nash, N.G. Fortson, et al. (1981)
• Adsorption of human serum albumin on the chrysotile surface: a molecular dynamics and spectroscopic investigation — R. Artali, A. Del Pra, et al. (2008)
• Adsorption of bovine serum albumin onto synthetic Fe-doped geomimetic chrysotile — A. Adamiano, I.G. Lesci, et al. (2015)

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