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Proteolysis of Iron Oxide-Associated Bovine Serum Albumin

Tian, Zhaomo LU ; Wang, Tao LU ; Tunlid, Anders LU and Persson, Per LU (2020) In Environmental Science & Technology 54(8). p.5121-5130
Abstract

Proteins are a substantial nitrogen source in soils provided that they can be hydrolyzed into bioavailable small peptides or amino acids. However, the strong associations between proteins and soil minerals restrict such proteolytic reactions. This study focused on how an extracellular fungal protease (Rhizopus sp.) hydrolyzed iron oxide-associated bovine serum albumin (BSA) and the factors that affected the proteolysis. We combined batch experiments with size-exclusion and reversed phase liquid chromatography and in situ infrared spectroscopic measurements to monitor the generation of proteolytic products in solution as well as the real-time changes of the adsorbed BSA during 24 h. Results showed that protease hydrolyzed the iron... (More)

Proteins are a substantial nitrogen source in soils provided that they can be hydrolyzed into bioavailable small peptides or amino acids. However, the strong associations between proteins and soil minerals restrict such proteolytic reactions. This study focused on how an extracellular fungal protease (Rhizopus sp.) hydrolyzed iron oxide-associated bovine serum albumin (BSA) and the factors that affected the proteolysis. We combined batch experiments with size-exclusion and reversed phase liquid chromatography and in situ infrared spectroscopic measurements to monitor the generation of proteolytic products in solution as well as the real-time changes of the adsorbed BSA during 24 h. Results showed that protease hydrolyzed the iron oxide-associated BSA directly at the surface without an initial desorption of BSA. Concurrently, the protease was adsorbed to vacant surface sites at the iron oxides, which significantly slowed down the rate of proteolysis. This inhibiting effect was counteracted by the presence of preadsorbed phosphate or by increasing the BSA coverage, which prevented protease adsorption. Fast initial rates of iron oxide-associated BSA proteolysis, comparable to proteolysis of BSA in solution, and very slow rates at prolonged proteolysis suggest a large variability in mineral-associated proteins as a nitrogen source in soils and that only a fraction of the protein is bioavailable.

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author
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organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Environmental Science & Technology
volume
54
issue
8
pages
10 pages
publisher
The American Chemical Society (ACS)
external identifiers
  • pmid:32208652
  • scopus:85083912980
ISSN
1520-5851
DOI
10.1021/acs.est.0c00860
project
MICCS - Molecular Interactions Controlling soil Carbon Sequestration
language
English
LU publication?
yes
id
57ff13fb-6ca6-4435-9453-b81062fd08d6
date added to LUP
2020-05-20 08:46:34
date last changed
2020-09-23 15:15:26
@article{57ff13fb-6ca6-4435-9453-b81062fd08d6,
  abstract     = {<p>Proteins are a substantial nitrogen source in soils provided that they can be hydrolyzed into bioavailable small peptides or amino acids. However, the strong associations between proteins and soil minerals restrict such proteolytic reactions. This study focused on how an extracellular fungal protease (Rhizopus sp.) hydrolyzed iron oxide-associated bovine serum albumin (BSA) and the factors that affected the proteolysis. We combined batch experiments with size-exclusion and reversed phase liquid chromatography and in situ infrared spectroscopic measurements to monitor the generation of proteolytic products in solution as well as the real-time changes of the adsorbed BSA during 24 h. Results showed that protease hydrolyzed the iron oxide-associated BSA directly at the surface without an initial desorption of BSA. Concurrently, the protease was adsorbed to vacant surface sites at the iron oxides, which significantly slowed down the rate of proteolysis. This inhibiting effect was counteracted by the presence of preadsorbed phosphate or by increasing the BSA coverage, which prevented protease adsorption. Fast initial rates of iron oxide-associated BSA proteolysis, comparable to proteolysis of BSA in solution, and very slow rates at prolonged proteolysis suggest a large variability in mineral-associated proteins as a nitrogen source in soils and that only a fraction of the protein is bioavailable.</p>},
  author       = {Tian, Zhaomo and Wang, Tao and Tunlid, Anders and Persson, Per},
  issn         = {1520-5851},
  language     = {eng},
  number       = {8},
  pages        = {5121--5130},
  publisher    = {The American Chemical Society (ACS)},
  series       = {Environmental Science & Technology},
  title        = {Proteolysis of Iron Oxide-Associated Bovine Serum Albumin},
  url          = {http://dx.doi.org/10.1021/acs.est.0c00860},
  doi          = {10.1021/acs.est.0c00860},
  volume       = {54},
  year         = {2020},
}