Ammonia production and kinetic properties of glutamate dehydrogenase in the sipinculid Phascolosoma arcuatum exposed to anoxia

Y. K. Ip, Kah-Whye Peng, S. F. Chew, R. W L Lim, G. Q. Tan

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

The amounts of total NH4 +detected in the external media in which Phascolosoma arcuatum had been exposed to various periods of anoxia were significantly greater than those in which the worms were exposed to normoxia for a similar period. The increased NH4 +production by P. arcuatum during anoxic exposure was unlikely to be due to an increased catabolism of adenine nucleotides or urea. In contrast, there were significant decreases in the concentrations of several free amino acids in the coelomic plasma and body tissues of individuals during the 48 h of anoxic exposure. The amount of NH4 +produced by the anoxic P. arcuatum could be accounted for by the decreases in the concentrations of aspartate or glycine. Increases in the catabolism of free amino acids (FAA), leading to the increased production of NH4 +, in P. arcuatum during anoxia were supported by the detection of significant changes in the kinetic properties of glutamate dehydrogenase (GDH), in the deaminating direction, from worms exposed to anoxia for 48 h. The apparent increase in the affinity of GDH from the anoxic worm to glutamate would bring about a greater deaminating activity at physiological concentrations of ths substrate. P. arcuatum used in these experiments were collected from the mangrove swamp at Mandai, Singapore between 1990 and 1993.

Original languageEnglish (US)
Pages (from-to)261-266
Number of pages6
JournalMarine Biology
Volume119
Issue number2
DOIs
StatePublished - May 1994
Externally publishedYes

Fingerprint

glutamate dehydrogenase
anoxia
hypoxia
ammonia
catabolism
kinetics
free amino acids
amino acid
mangrove swamps
metabolism
normoxia
Singapore
aspartic acid
glycine (amino acid)
glutamates
mangrove
urea
plasma
substrate
experiment

ASJC Scopus subject areas

  • Aquatic Science

Cite this

Ammonia production and kinetic properties of glutamate dehydrogenase in the sipinculid Phascolosoma arcuatum exposed to anoxia. / Ip, Y. K.; Peng, Kah-Whye; Chew, S. F.; Lim, R. W L; Tan, G. Q.

In: Marine Biology, Vol. 119, No. 2, 05.1994, p. 261-266.

Research output: Contribution to journalArticle

@article{4690580e04a44ae68c007040eb282937,
title = "Ammonia production and kinetic properties of glutamate dehydrogenase in the sipinculid Phascolosoma arcuatum exposed to anoxia",
abstract = "The amounts of total NH4 +detected in the external media in which Phascolosoma arcuatum had been exposed to various periods of anoxia were significantly greater than those in which the worms were exposed to normoxia for a similar period. The increased NH4 +production by P. arcuatum during anoxic exposure was unlikely to be due to an increased catabolism of adenine nucleotides or urea. In contrast, there were significant decreases in the concentrations of several free amino acids in the coelomic plasma and body tissues of individuals during the 48 h of anoxic exposure. The amount of NH4 +produced by the anoxic P. arcuatum could be accounted for by the decreases in the concentrations of aspartate or glycine. Increases in the catabolism of free amino acids (FAA), leading to the increased production of NH4 +, in P. arcuatum during anoxia were supported by the detection of significant changes in the kinetic properties of glutamate dehydrogenase (GDH), in the deaminating direction, from worms exposed to anoxia for 48 h. The apparent increase in the affinity of GDH from the anoxic worm to glutamate would bring about a greater deaminating activity at physiological concentrations of ths substrate. P. arcuatum used in these experiments were collected from the mangrove swamp at Mandai, Singapore between 1990 and 1993.",
author = "Ip, {Y. K.} and Kah-Whye Peng and Chew, {S. F.} and Lim, {R. W L} and Tan, {G. Q.}",
year = "1994",
month = "5",
doi = "10.1007/BF00349565",
language = "English (US)",
volume = "119",
pages = "261--266",
journal = "Marine Biology",
issn = "0025-3162",
publisher = "Springer Verlag",
number = "2",

}

TY - JOUR

T1 - Ammonia production and kinetic properties of glutamate dehydrogenase in the sipinculid Phascolosoma arcuatum exposed to anoxia

AU - Ip, Y. K.

AU - Peng, Kah-Whye

AU - Chew, S. F.

AU - Lim, R. W L

AU - Tan, G. Q.

PY - 1994/5

Y1 - 1994/5

N2 - The amounts of total NH4 +detected in the external media in which Phascolosoma arcuatum had been exposed to various periods of anoxia were significantly greater than those in which the worms were exposed to normoxia for a similar period. The increased NH4 +production by P. arcuatum during anoxic exposure was unlikely to be due to an increased catabolism of adenine nucleotides or urea. In contrast, there were significant decreases in the concentrations of several free amino acids in the coelomic plasma and body tissues of individuals during the 48 h of anoxic exposure. The amount of NH4 +produced by the anoxic P. arcuatum could be accounted for by the decreases in the concentrations of aspartate or glycine. Increases in the catabolism of free amino acids (FAA), leading to the increased production of NH4 +, in P. arcuatum during anoxia were supported by the detection of significant changes in the kinetic properties of glutamate dehydrogenase (GDH), in the deaminating direction, from worms exposed to anoxia for 48 h. The apparent increase in the affinity of GDH from the anoxic worm to glutamate would bring about a greater deaminating activity at physiological concentrations of ths substrate. P. arcuatum used in these experiments were collected from the mangrove swamp at Mandai, Singapore between 1990 and 1993.

AB - The amounts of total NH4 +detected in the external media in which Phascolosoma arcuatum had been exposed to various periods of anoxia were significantly greater than those in which the worms were exposed to normoxia for a similar period. The increased NH4 +production by P. arcuatum during anoxic exposure was unlikely to be due to an increased catabolism of adenine nucleotides or urea. In contrast, there were significant decreases in the concentrations of several free amino acids in the coelomic plasma and body tissues of individuals during the 48 h of anoxic exposure. The amount of NH4 +produced by the anoxic P. arcuatum could be accounted for by the decreases in the concentrations of aspartate or glycine. Increases in the catabolism of free amino acids (FAA), leading to the increased production of NH4 +, in P. arcuatum during anoxia were supported by the detection of significant changes in the kinetic properties of glutamate dehydrogenase (GDH), in the deaminating direction, from worms exposed to anoxia for 48 h. The apparent increase in the affinity of GDH from the anoxic worm to glutamate would bring about a greater deaminating activity at physiological concentrations of ths substrate. P. arcuatum used in these experiments were collected from the mangrove swamp at Mandai, Singapore between 1990 and 1993.

UR - http://www.scopus.com/inward/record.url?scp=0028140979&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0028140979&partnerID=8YFLogxK

U2 - 10.1007/BF00349565

DO - 10.1007/BF00349565

M3 - Article

AN - SCOPUS:0028140979

VL - 119

SP - 261

EP - 266

JO - Marine Biology

JF - Marine Biology

SN - 0025-3162

IS - 2

ER -