Microbial activation of two serine enzymes and prophenoloxidase in the plasma fraction of hemolymph of the silkworm, Bombyx mori

Hideya Yoshida, Masaaki Ashida

Research output: Contribution to journalArticle

84 Citations (Scopus)

Abstract

Elicitors, such as zymosan and cell wall fractions of Gram-negative and Gram-positive bacteria, initiated the activation of two serine enzymes in silkworm plasma. One of them is an esterase capable of hydrolyzing a synthetic substrate for tryptic activity, N-α-benzoyl-l-arginine ethyl ester and the other is prophenoloxidase activating enzyme (PPAE) which converts prophenoloxidase into the active enzyme. Activities of the esterase and PPAE appeared sequentially during the incubation of plasma with the elicitor and were short-lived after activation. These serine enzymes were insensitive to diisopropylfluorophosphate before activation but became sensitive upon activation, suggesting that they may be present as zymogens in plasma. Both Gram-negative and Gram-positive bacterial cell wall preparations lost almost completely their abilities to initiate the activation of the enzymes after treatment with egg white lysozyme. Peptidoglycan isolated from Gram-positive bacteria initiated the activation of the enzymes in plasma at a concentration of a few ng/ml. These results together with the inability of lipopolysaccharides to activate the serine enzymes, strongly suggest that the active principle of bacterial cell walls is peptidoglycan.

Original languageEnglish
Pages (from-to)539-545
Number of pages7
JournalInsect Biochemistry
Volume16
Issue number3
DOIs
Publication statusPublished - 1986
Externally publishedYes

Fingerprint

prophenoloxidase
Bombyx
Hemolymph
Bombyx mori
silkworms
serine
Serine
hemolymph
Chemical activation
Cell Wall
Plasmas
Enzyme Activation
Peptidoglycan
Gram-Positive Bacteria
Esterases
Enzymes
enzymes
enzyme activation
peptidoglycans
Cells

Keywords

  • hemolymph
  • lipopolysaccharide and silkworm
  • lysozyme
  • peptidoglycan
  • Phenoloxidase
  • protease

Cite this

Microbial activation of two serine enzymes and prophenoloxidase in the plasma fraction of hemolymph of the silkworm, Bombyx mori. / Yoshida, Hideya; Ashida, Masaaki.

In: Insect Biochemistry, Vol. 16, No. 3, 1986, p. 539-545.

Research output: Contribution to journalArticle

@article{b1712734559747c6b19ece97cee5043b,
title = "Microbial activation of two serine enzymes and prophenoloxidase in the plasma fraction of hemolymph of the silkworm, Bombyx mori",
abstract = "Elicitors, such as zymosan and cell wall fractions of Gram-negative and Gram-positive bacteria, initiated the activation of two serine enzymes in silkworm plasma. One of them is an esterase capable of hydrolyzing a synthetic substrate for tryptic activity, N-α-benzoyl-l-arginine ethyl ester and the other is prophenoloxidase activating enzyme (PPAE) which converts prophenoloxidase into the active enzyme. Activities of the esterase and PPAE appeared sequentially during the incubation of plasma with the elicitor and were short-lived after activation. These serine enzymes were insensitive to diisopropylfluorophosphate before activation but became sensitive upon activation, suggesting that they may be present as zymogens in plasma. Both Gram-negative and Gram-positive bacterial cell wall preparations lost almost completely their abilities to initiate the activation of the enzymes after treatment with egg white lysozyme. Peptidoglycan isolated from Gram-positive bacteria initiated the activation of the enzymes in plasma at a concentration of a few ng/ml. These results together with the inability of lipopolysaccharides to activate the serine enzymes, strongly suggest that the active principle of bacterial cell walls is peptidoglycan.",
keywords = "hemolymph, lipopolysaccharide and silkworm, lysozyme, peptidoglycan, Phenoloxidase, protease",
author = "Hideya Yoshida and Masaaki Ashida",
year = "1986",
doi = "10.1016/0020-1790(86)90031-4",
language = "English",
volume = "16",
pages = "539--545",
journal = "Insect Biochemistry and Molecular Biology",
issn = "0965-1748",
publisher = "Elsevier Limited",
number = "3",

}

TY - JOUR

T1 - Microbial activation of two serine enzymes and prophenoloxidase in the plasma fraction of hemolymph of the silkworm, Bombyx mori

AU - Yoshida, Hideya

AU - Ashida, Masaaki

PY - 1986

Y1 - 1986

N2 - Elicitors, such as zymosan and cell wall fractions of Gram-negative and Gram-positive bacteria, initiated the activation of two serine enzymes in silkworm plasma. One of them is an esterase capable of hydrolyzing a synthetic substrate for tryptic activity, N-α-benzoyl-l-arginine ethyl ester and the other is prophenoloxidase activating enzyme (PPAE) which converts prophenoloxidase into the active enzyme. Activities of the esterase and PPAE appeared sequentially during the incubation of plasma with the elicitor and were short-lived after activation. These serine enzymes were insensitive to diisopropylfluorophosphate before activation but became sensitive upon activation, suggesting that they may be present as zymogens in plasma. Both Gram-negative and Gram-positive bacterial cell wall preparations lost almost completely their abilities to initiate the activation of the enzymes after treatment with egg white lysozyme. Peptidoglycan isolated from Gram-positive bacteria initiated the activation of the enzymes in plasma at a concentration of a few ng/ml. These results together with the inability of lipopolysaccharides to activate the serine enzymes, strongly suggest that the active principle of bacterial cell walls is peptidoglycan.

AB - Elicitors, such as zymosan and cell wall fractions of Gram-negative and Gram-positive bacteria, initiated the activation of two serine enzymes in silkworm plasma. One of them is an esterase capable of hydrolyzing a synthetic substrate for tryptic activity, N-α-benzoyl-l-arginine ethyl ester and the other is prophenoloxidase activating enzyme (PPAE) which converts prophenoloxidase into the active enzyme. Activities of the esterase and PPAE appeared sequentially during the incubation of plasma with the elicitor and were short-lived after activation. These serine enzymes were insensitive to diisopropylfluorophosphate before activation but became sensitive upon activation, suggesting that they may be present as zymogens in plasma. Both Gram-negative and Gram-positive bacterial cell wall preparations lost almost completely their abilities to initiate the activation of the enzymes after treatment with egg white lysozyme. Peptidoglycan isolated from Gram-positive bacteria initiated the activation of the enzymes in plasma at a concentration of a few ng/ml. These results together with the inability of lipopolysaccharides to activate the serine enzymes, strongly suggest that the active principle of bacterial cell walls is peptidoglycan.

KW - hemolymph

KW - lipopolysaccharide and silkworm

KW - lysozyme

KW - peptidoglycan

KW - Phenoloxidase

KW - protease

UR - http://www.scopus.com/inward/record.url?scp=0001310379&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0001310379&partnerID=8YFLogxK

U2 - 10.1016/0020-1790(86)90031-4

DO - 10.1016/0020-1790(86)90031-4

M3 - Article

VL - 16

SP - 539

EP - 545

JO - Insect Biochemistry and Molecular Biology

JF - Insect Biochemistry and Molecular Biology

SN - 0965-1748

IS - 3

ER -