Serum-Mediated Cleavage of Bacillus anthracis Protective Antigen Is a Two-Step Process That Involves a Serum Carboxypeptidase

David L. Goldman, Edward Nieves, Antonio Nakouzi, Johanna Rivera, Ei Ei Phyu, Than Htut Win, Jacqueline M. Achkar, Arturo Casadevall

Research output: Contribution to journalArticle

Abstract

Much of our understanding of the activity of anthrax toxin is based on in vitro systems, which delineate the interaction between Bacillus anthracis toxins and the cell surface. However, these systems fail to account for the intimate association of B. anthracis with the circulatory system, including the contribution of serum proteins to the host response and processing of anthrax toxins. Using a variety of immunological techniques to inhibit serum processing of B. anthracis protective antigen (PA) along with mass spectrometry analysis, we demonstrate that serum digests PA via 2 distinct reactions. In the first reaction, serum cleaves PA83 into 2 fragments to produce PA63 and PA20 fragments, similarly to that observed following furin digestion. This is followed by carboxypeptidase-mediated removal of the carboxy-terminal arginine and lysines from PA20IMPORTANCE Our findings identify a serum-mediated modification of PA20 that has not been previously described. These observations further imply that the processing of PA is more complex than currently thought. Additional study is needed to define the contribution of serum processing of PA to the host response and individual susceptibility to anthrax.

Original languageEnglish (US)
JournalmSphere
Volume3
Issue number3
DOIs
StatePublished - Jun 27 2018

Fingerprint

Carboxypeptidases
Serum
Antigen Presentation
Furin
Immunologic Techniques
Antigens
Bacillus anthracis
Anthrax
Cardiovascular System
Lysine
Arginine
Blood Proteins
Digestion
Mass Spectrometry
anthrax toxin

Keywords

  • anthrax
  • proteases
  • toxin

ASJC Scopus subject areas

  • Microbiology
  • Molecular Biology

Cite this

Serum-Mediated Cleavage of Bacillus anthracis Protective Antigen Is a Two-Step Process That Involves a Serum Carboxypeptidase. / Goldman, David L.; Nieves, Edward; Nakouzi, Antonio; Rivera, Johanna; Phyu, Ei Ei; Win, Than Htut; Achkar, Jacqueline M.; Casadevall, Arturo.

In: mSphere, Vol. 3, No. 3, 27.06.2018.

Research output: Contribution to journalArticle

@article{2fc49401de964eaab7812de47394a7a2,
title = "Serum-Mediated Cleavage of Bacillus anthracis Protective Antigen Is a Two-Step Process That Involves a Serum Carboxypeptidase",
abstract = "Much of our understanding of the activity of anthrax toxin is based on in vitro systems, which delineate the interaction between Bacillus anthracis toxins and the cell surface. However, these systems fail to account for the intimate association of B. anthracis with the circulatory system, including the contribution of serum proteins to the host response and processing of anthrax toxins. Using a variety of immunological techniques to inhibit serum processing of B. anthracis protective antigen (PA) along with mass spectrometry analysis, we demonstrate that serum digests PA via 2 distinct reactions. In the first reaction, serum cleaves PA83 into 2 fragments to produce PA63 and PA20 fragments, similarly to that observed following furin digestion. This is followed by carboxypeptidase-mediated removal of the carboxy-terminal arginine and lysines from PA20IMPORTANCE Our findings identify a serum-mediated modification of PA20 that has not been previously described. These observations further imply that the processing of PA is more complex than currently thought. Additional study is needed to define the contribution of serum processing of PA to the host response and individual susceptibility to anthrax.",
keywords = "anthrax, proteases, toxin",
author = "Goldman, {David L.} and Edward Nieves and Antonio Nakouzi and Johanna Rivera and Phyu, {Ei Ei} and Win, {Than Htut} and Achkar, {Jacqueline M.} and Arturo Casadevall",
year = "2018",
month = "6",
day = "27",
doi = "10.1128/mSphere.00091-18",
language = "English (US)",
volume = "3",
journal = "mSphere",
issn = "2379-5042",
publisher = "American Society for Microbiology",
number = "3",

}

TY - JOUR

T1 - Serum-Mediated Cleavage of Bacillus anthracis Protective Antigen Is a Two-Step Process That Involves a Serum Carboxypeptidase

AU - Goldman, David L.

AU - Nieves, Edward

AU - Nakouzi, Antonio

AU - Rivera, Johanna

AU - Phyu, Ei Ei

AU - Win, Than Htut

AU - Achkar, Jacqueline M.

AU - Casadevall, Arturo

PY - 2018/6/27

Y1 - 2018/6/27

N2 - Much of our understanding of the activity of anthrax toxin is based on in vitro systems, which delineate the interaction between Bacillus anthracis toxins and the cell surface. However, these systems fail to account for the intimate association of B. anthracis with the circulatory system, including the contribution of serum proteins to the host response and processing of anthrax toxins. Using a variety of immunological techniques to inhibit serum processing of B. anthracis protective antigen (PA) along with mass spectrometry analysis, we demonstrate that serum digests PA via 2 distinct reactions. In the first reaction, serum cleaves PA83 into 2 fragments to produce PA63 and PA20 fragments, similarly to that observed following furin digestion. This is followed by carboxypeptidase-mediated removal of the carboxy-terminal arginine and lysines from PA20IMPORTANCE Our findings identify a serum-mediated modification of PA20 that has not been previously described. These observations further imply that the processing of PA is more complex than currently thought. Additional study is needed to define the contribution of serum processing of PA to the host response and individual susceptibility to anthrax.

AB - Much of our understanding of the activity of anthrax toxin is based on in vitro systems, which delineate the interaction between Bacillus anthracis toxins and the cell surface. However, these systems fail to account for the intimate association of B. anthracis with the circulatory system, including the contribution of serum proteins to the host response and processing of anthrax toxins. Using a variety of immunological techniques to inhibit serum processing of B. anthracis protective antigen (PA) along with mass spectrometry analysis, we demonstrate that serum digests PA via 2 distinct reactions. In the first reaction, serum cleaves PA83 into 2 fragments to produce PA63 and PA20 fragments, similarly to that observed following furin digestion. This is followed by carboxypeptidase-mediated removal of the carboxy-terminal arginine and lysines from PA20IMPORTANCE Our findings identify a serum-mediated modification of PA20 that has not been previously described. These observations further imply that the processing of PA is more complex than currently thought. Additional study is needed to define the contribution of serum processing of PA to the host response and individual susceptibility to anthrax.

KW - anthrax

KW - proteases

KW - toxin

UR - http://www.scopus.com/inward/record.url?scp=85055139906&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85055139906&partnerID=8YFLogxK

U2 - 10.1128/mSphere.00091-18

DO - 10.1128/mSphere.00091-18

M3 - Article

VL - 3

JO - mSphere

JF - mSphere

SN - 2379-5042

IS - 3

ER -