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Proteolysis of Iron Oxide-Associated Bovine Serum Albumin

[Image: see text] 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 extracellu...

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Autores principales: Tian, Zhaomo, Wang, Tao, Tunlid, Anders, Persson, Per
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Chemical Society 2020
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7311061/
https://www.ncbi.nlm.nih.gov/pubmed/32208652
http://dx.doi.org/10.1021/acs.est.0c00860
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author Tian, Zhaomo
Wang, Tao
Tunlid, Anders
Persson, Per
author_facet Tian, Zhaomo
Wang, Tao
Tunlid, Anders
Persson, Per
author_sort Tian, Zhaomo
collection PubMed
description [Image: see text] 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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spelling pubmed-73110612020-06-24 Proteolysis of Iron Oxide-Associated Bovine Serum Albumin Tian, Zhaomo Wang, Tao Tunlid, Anders Persson, Per Environ Sci Technol [Image: see text] 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. American Chemical Society 2020-03-25 2020-04-21 /pmc/articles/PMC7311061/ /pubmed/32208652 http://dx.doi.org/10.1021/acs.est.0c00860 Text en Copyright © 2020 American Chemical Society This is an open access article published under a Creative Commons Attribution (CC-BY) License (http://pubs.acs.org/page/policy/authorchoice_ccby_termsofuse.html) , which permits unrestricted use, distribution and reproduction in any medium, provided the author and source are cited.
spellingShingle Tian, Zhaomo
Wang, Tao
Tunlid, Anders
Persson, Per
Proteolysis of Iron Oxide-Associated Bovine Serum Albumin
title Proteolysis of Iron Oxide-Associated Bovine Serum Albumin
title_full Proteolysis of Iron Oxide-Associated Bovine Serum Albumin
title_fullStr Proteolysis of Iron Oxide-Associated Bovine Serum Albumin
title_full_unstemmed Proteolysis of Iron Oxide-Associated Bovine Serum Albumin
title_short Proteolysis of Iron Oxide-Associated Bovine Serum Albumin
title_sort proteolysis of iron oxide-associated bovine serum albumin
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7311061/
https://www.ncbi.nlm.nih.gov/pubmed/32208652
http://dx.doi.org/10.1021/acs.est.0c00860
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