THE IONIC CHANNELS FORMED BY CHOLERA-TOXIN IN PLANAR BILAYER LIPID-MEMBRANES ARE ENTIRELY ATTRIBUTABLE TO ITS B-SUBUNIT

被引：37

作者：

KRASILNIKOV, OV ^{[1
]}

MURATKHODJAEV, JN ^{[1
]}

VORONOV, SE ^{[1
]}

YEZEPCHUK, YV ^{[1
]}

机构：

[1] NF GAMALEYA EPIDEMIOL & MICROBIOL RES INST,MOSCOW,USSR

来源：

BIOCHIMICA ET BIOPHYSICA ACTA | 1991年 / 1067卷 / 02期

关键词：

CHOLERA TOXIN; IONIC CHANNEL; PLANAR BILAYER; LIPID MEMBRANE;

D O I：

10.1016/0005-2736(91)90039-B

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

The interaction of cholera toxin with planar bilayer lipid membranes (BLM) at low Ph results in the formation of ionic channels, the conductance of which can be directly measured in voltage-clamp experiments. It is found that the B-subunit of cholera toxin (CT-B) also is able to induce ionic channels in BLM whereas the A-subunit is not able to do it. The increase of pH inhibited the channel-forming activity of CT-B. The investigation of pH-dependences of both the conductance and the cation-anion selectivity of the CT-B channel allowed us to suggest that the water pore of this channel is confined to the B-subunit of cholera toxin. The effective diameter of the CT-B channels water pores was directly measured in BLM and is equal to 2.1 +/- 0.2 nm. The channels formed by whole toxin and its B-subunit exhibit voltage-dependent activity. We believe these channels are relevant to the mode of action of cholera toxin and especially to the endosomal pathway of the A-subunit into cells.

引用

页码：166 / 170

页数：5

共 35 条

[1]

BERGELSON LD, 1981, PREPARATIVE BIOCH LI, P66

[2] THE N-TERMINAL HALF OF THE HEAVY-CHAIN OF BOTULINUM TYPE A NEUROTOXIN FORMS CHANNELS IN PLANAR PHOSPHOLIPID-BILAYERS [J].

BLAUSTEIN, RO ;

GERMANN, WJ ;

FINKELSTEIN, A ;

DASGUPTA, BR .

FEBS LETTERS, 1987, 226 (01) :115-120

[3] TETANUS TOXIN FRAGMENT FORMS CHANNELS IN LIPID VESICLES AT LOW PH [J].

BOQUET, P ;

DUFLOT, E .

PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA-BIOLOGICAL SCIENCES, 1982, 79 (24) :7614-7618

[4]

BULLOCK JO, 1983, J BIOL CHEM, V258, P9908

[5] VOLTAGE GATING IN THE MITOCHONDRIAL CHANNEL, VDAC [J].

COLOMBINI, M .

JOURNAL OF MEMBRANE BIOLOGY, 1989, 111 (02) :103-111

[6] LOCALIZATION IN DIPHTHERIA-TOXIN FRAGMENT-B OF A REGION THAT INDUCES PORE FORMATION IN PLANAR LIPID BILAYERS AT LOW PH [J].

DELEERS, M ;

BEUGNIER, N ;

FALMAGNE, P ;

CABIAUX, V ;

RUYSSCHAERT, JM .

FEBS LETTERS, 1983, 160 (1-2) :82-86

[7]

DEWOLF M, 1982, ARCH INT PHYSIOL BIO, V90, pB110

[8] STRUCTURAL FEATURES OF THE BINDING-SITE OF CHOLERA-TOXIN INFERRED FROM FLUORESCENCE MEASUREMENTS [J].

DEWOLF, M ;

VANDESSEL, G ;

LAGROU, A ;

HILDERSON, HJ ;

DIERICK, W .

BIOCHIMICA ET BIOPHYSICA ACTA, 1985, 832 (02) :165-174

[9] PH-INDUCED TRANSITIONS IN CHOLERA-TOXIN CONFORMATION - A FLUORESCENCE STUDY [J].

DEWOLF, MJS ;

VANDESSEL, GAF ;

LAGROU, AR ;

HILDERSON, HJJ ;

DIERICK, WSH .

BIOCHEMISTRY, 1987, 26 (13) :3799-3806

[10]

ERMISHKIN LN, 1989, BIOCHIM BIOPHYS ACTA, V1081, P161

← 1 2 3 4 →