Uptake of lysine and proline via separate α-neutral amino acid transport pathways in Mytilus gill brush border membranes

Ana M. Pajor, Stephen Wright

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5 Citations (Scopus)

Abstract

Brush border membrane vesicles (BBMV) were prepared from the gills of the marine mussel, Mytilus edulis. These membranes contained two distinct pathways for cotransport of Na+ and α-neutral amino acids. The major pathway in mussel gill BBMV was the alanine-lysine (AK) pathway, which had a high affinity for alanine and for the cationic amino acid, lysine. The AK pathway was inhibited by nonpolar α-neutral amino acids and cationic amino acids, but was not affected by β-neutral amino acids or imino acids. The kinetics of lysine transport were consistent with a single saturable process, with a Jmax of 550 pmol/mg-min and a Kt of 5 μm. The AK pathway did not have a strict requirement for Na+, and concentrative transport of lysine was seen in the presence of inwardly directed gradients of Li+ and K+, as well as Na+. Harmaline inhibited the transport of lysine in solutions containing either Na+ or K+. The alanine-proline (AP) pathway transported both alanine and proline in mussel gill BBMV. The AP pathway was strongly inhibited by nonpolar α-neutral amino acids, proline, and α-(methylamino)isobutyric acid (Me-AIB). The kinetics of proline transport were described by a single saturable process, with a Jmax of 180 pmol/mg-min and Kt of 4 μm. In contrast to the AK pathway, the AP pathway appeared to have a strict requirement for Na+. Na+-activation experiments with lysine and proline revealed sigmoid kinetics, indicating that multiple Na+ ions are involved in the transport of these substrates. The transport of both lysine and proline was affected by membrane potential in a manner consistent with electrogenic transport.

Original languageEnglish (US)
Pages (from-to)237-247
Number of pages11
JournalThe Journal of Membrane Biology
Volume107
Issue number3
DOIs
StatePublished - Mar 1989

Fingerprint

Mytilus
Neutral Amino Acids
Microvilli
Proline
Lysine
Alanine
Membranes
Bivalvia
Harmaline
Imino Acids
Mytilus edulis
Amino Acids
Sigmoid Colon
Membrane Potentials
Ions

Keywords

  • alanine transport
  • brush-border membrane vesicles
  • lysine transport
  • Mytilus edulis
  • Na-cotransport
  • proline transport

ASJC Scopus subject areas

  • Physiology
  • Cell Biology
  • Biophysics

Cite this

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title = "Uptake of lysine and proline via separate α-neutral amino acid transport pathways in Mytilus gill brush border membranes",
abstract = "Brush border membrane vesicles (BBMV) were prepared from the gills of the marine mussel, Mytilus edulis. These membranes contained two distinct pathways for cotransport of Na+ and α-neutral amino acids. The major pathway in mussel gill BBMV was the alanine-lysine (AK) pathway, which had a high affinity for alanine and for the cationic amino acid, lysine. The AK pathway was inhibited by nonpolar α-neutral amino acids and cationic amino acids, but was not affected by β-neutral amino acids or imino acids. The kinetics of lysine transport were consistent with a single saturable process, with a Jmax of 550 pmol/mg-min and a Kt of 5 μm. The AK pathway did not have a strict requirement for Na+, and concentrative transport of lysine was seen in the presence of inwardly directed gradients of Li+ and K+, as well as Na+. Harmaline inhibited the transport of lysine in solutions containing either Na+ or K+. The alanine-proline (AP) pathway transported both alanine and proline in mussel gill BBMV. The AP pathway was strongly inhibited by nonpolar α-neutral amino acids, proline, and α-(methylamino)isobutyric acid (Me-AIB). The kinetics of proline transport were described by a single saturable process, with a Jmax of 180 pmol/mg-min and Kt of 4 μm. In contrast to the AK pathway, the AP pathway appeared to have a strict requirement for Na+. Na+-activation experiments with lysine and proline revealed sigmoid kinetics, indicating that multiple Na+ ions are involved in the transport of these substrates. The transport of both lysine and proline was affected by membrane potential in a manner consistent with electrogenic transport.",
keywords = "alanine transport, brush-border membrane vesicles, lysine transport, Mytilus edulis, Na-cotransport, proline transport",
author = "Pajor, {Ana M.} and Stephen Wright",
year = "1989",
month = "3",
doi = "10.1007/BF01871939",
language = "English (US)",
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TY - JOUR

T1 - Uptake of lysine and proline via separate α-neutral amino acid transport pathways in Mytilus gill brush border membranes

AU - Pajor, Ana M.

AU - Wright, Stephen

PY - 1989/3

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N2 - Brush border membrane vesicles (BBMV) were prepared from the gills of the marine mussel, Mytilus edulis. These membranes contained two distinct pathways for cotransport of Na+ and α-neutral amino acids. The major pathway in mussel gill BBMV was the alanine-lysine (AK) pathway, which had a high affinity for alanine and for the cationic amino acid, lysine. The AK pathway was inhibited by nonpolar α-neutral amino acids and cationic amino acids, but was not affected by β-neutral amino acids or imino acids. The kinetics of lysine transport were consistent with a single saturable process, with a Jmax of 550 pmol/mg-min and a Kt of 5 μm. The AK pathway did not have a strict requirement for Na+, and concentrative transport of lysine was seen in the presence of inwardly directed gradients of Li+ and K+, as well as Na+. Harmaline inhibited the transport of lysine in solutions containing either Na+ or K+. The alanine-proline (AP) pathway transported both alanine and proline in mussel gill BBMV. The AP pathway was strongly inhibited by nonpolar α-neutral amino acids, proline, and α-(methylamino)isobutyric acid (Me-AIB). The kinetics of proline transport were described by a single saturable process, with a Jmax of 180 pmol/mg-min and Kt of 4 μm. In contrast to the AK pathway, the AP pathway appeared to have a strict requirement for Na+. Na+-activation experiments with lysine and proline revealed sigmoid kinetics, indicating that multiple Na+ ions are involved in the transport of these substrates. The transport of both lysine and proline was affected by membrane potential in a manner consistent with electrogenic transport.

AB - Brush border membrane vesicles (BBMV) were prepared from the gills of the marine mussel, Mytilus edulis. These membranes contained two distinct pathways for cotransport of Na+ and α-neutral amino acids. The major pathway in mussel gill BBMV was the alanine-lysine (AK) pathway, which had a high affinity for alanine and for the cationic amino acid, lysine. The AK pathway was inhibited by nonpolar α-neutral amino acids and cationic amino acids, but was not affected by β-neutral amino acids or imino acids. The kinetics of lysine transport were consistent with a single saturable process, with a Jmax of 550 pmol/mg-min and a Kt of 5 μm. The AK pathway did not have a strict requirement for Na+, and concentrative transport of lysine was seen in the presence of inwardly directed gradients of Li+ and K+, as well as Na+. Harmaline inhibited the transport of lysine in solutions containing either Na+ or K+. The alanine-proline (AP) pathway transported both alanine and proline in mussel gill BBMV. The AP pathway was strongly inhibited by nonpolar α-neutral amino acids, proline, and α-(methylamino)isobutyric acid (Me-AIB). The kinetics of proline transport were described by a single saturable process, with a Jmax of 180 pmol/mg-min and Kt of 4 μm. In contrast to the AK pathway, the AP pathway appeared to have a strict requirement for Na+. Na+-activation experiments with lysine and proline revealed sigmoid kinetics, indicating that multiple Na+ ions are involved in the transport of these substrates. The transport of both lysine and proline was affected by membrane potential in a manner consistent with electrogenic transport.

KW - alanine transport

KW - brush-border membrane vesicles

KW - lysine transport

KW - Mytilus edulis

KW - Na-cotransport

KW - proline transport

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JO - Journal of Membrane Biology

JF - Journal of Membrane Biology

SN - 0022-2631

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