A hydrophobic form of the small-intestinal sucrase-isomaltase complex

Sigrist, Hans; Ronner, Peter; Semenza, Giorgio

doi:10.1016/0005-2736(75)90022-x

Cited by 102 publications

(34 citation statements)

References 28 publications

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“…Binding activity of the rCPE variants was determined using a previously described (32) competition assay of 125 I-labeled CPE binding to rabbit brush border membranes (BBMs). These membranes were isolated by a previously described protocol (29) from New Zealand White rabbits. This animal work was approved by Animal Care and Use Committee protocol 11594 from the University of California, Davis.…”

Section: Methodsmentioning

confidence: 99%

Identification of a Prepore Large-Complex Stage in the Mechanism of Action of Clostridium perfringens Enterotoxin

2007

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Clostridium perfringens enterotoxin (CPE) is the etiological agent of the third most common food-borne illness in the United States. The enteropathogenic effects of CPE result from formation of large CPEcontaining complexes in eukaryotic cell membranes. Formation of these ϳ155-and ϳ200-kDa complexes coincides with plasma membrane permeability changes in eukaryotic cells, causing a Ca 2؉ influx that drives cell death pathways. CPE contains a stretch of amino acids (residues 81 to 106) that alternates markedly in side chain polarity (a pattern shared by the transmembrane domains of the ␤-barrel pore-forming toxin family). The goal of this study, therefore, was to investigate whether this CPE region is involved in pore formation. Complete deletion of the CPE region from 81 to 106 produced a CPE variant that was noncytotoxic for Caco-2 cells and was unable to form CPE pores. However, this variant maintained the ability to form the ϳ155-kDa large complex. This large complex appears to be a prepore present on the plasma membrane surface since it showed greater susceptibility to proteases, increased complex instability, and a higher degree of dissociation from membranes compared to the large complex formed by recombinant CPE. When a D48A mutation was engineered into this prepore-forming CPE variant, the resultant variant was unable to form any prepore ϳ155-kDa large complex. Collectively these findings reveal a new step in CPE action, whereby receptor binding is followed by formation of a prepore large complex, which then inserts into membranes to form a pore.

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Section: Methodsmentioning

confidence: 99%

Identification of a Prepore Large-Complex Stage in the Mechanism of Action of Clostridium perfringens Enterotoxin

2007

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“…Small-intestine BBMs were isolated from female New Zealand White rabbits as described previously (33). […”

Section: Methodsmentioning

confidence: 99%

Fine Mapping of the N-Terminal Cytotoxicity Region of Clostridium perfringens Enterotoxin by Site-Directed Mutagenesis

Smedley

McClane

2004

Infect Immun

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Clostridium perfringens enterotoxin (CPE) has a unique mechanism of action that results in the formation of large, sodium dodecyl sulfate-resistant complexes involving tight junction proteins; those complexes then induce plasma membrane permeability alterations in host intestinal epithelial cells, leading to cell death and epithelial desquamation. Previous deletion and point mutational studies mapped CPE receptor binding activity to the toxin's extreme C terminus. Those earlier analyses also determined that an N-terminal CPE region between residues D45 and G53 is required for large complex formation and cytotoxicity. To more finely map this N-terminal cytotoxicity region, site-directed mutagenesis was performed with recombinant CPE (rCPE). Alanine-scanning mutagenesis produced one rCPE variant, D48A, that failed to form large complexes or induce cytotoxicity, despite having normal ability to bind and form the small complex. Two saturation variants, D48E and D48N, also had a phenotype resembling that of the D48A variant, indicating that both size and charge are important at CPE residue 48. Another alanine substitution rCPE variant, I51A, was highly attenuated for large complex formation and cytotoxicity, but rCPE saturation variants I51L and I51V displayed a normal large complex formation and cytotoxicity phenotype. Collectively, these mutagenesis results identify a core CPE sequence extending from residues G47 to I51 that directly participates in large complex formation and cytotoxicity.

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“…No significant difference in the overall composition of asymmetric uersus globular forms of acetylcholinesterase, however, appeared. This was in fact to be expected ; although the hydrophobic peptides which may be split from detergent-solubilized aminopeptidase or maltase by trypsin were soluble in chloroform/methanol mixtures, their amino acid compositions were not extremely biased in favour of hydrophobic amino acid residues [26], and an attempt to differentiate the overall composition of the intact and trypsin-treated forms of maltase has proved unsuccessful [25]. Whether it is a collagen-like component of the basement membrane, or a hydrophobic membranebound anchor, it seems obvious that the tail somehow plays a well-defined structural role in relation to the localisation of acetylcholinesterase.…”

Section: The Problem Of Tlzr Tail Subunits Amino Acid Compositionmentioning

confidence: 97%

“…If, on the other hand, the tail anchors the enzyme into the plasmic membrane, in a manner analogous to the hydrophobic peptides found in cytochrome b, [23], cytochrome b5 reductase [24] or intestinal brush border enzymes, such as aminopeptidase or sucraseisomaltase [25,26], it may be rich in hydrophobic amino acids. No significant difference in the overall composition of asymmetric uersus globular forms of acetylcholinesterase, however, appeared.…”

Section: The Problem Of Tlzr Tail Subunits Amino Acid Compositionmentioning

confidence: 99%

Molecular Forms of Electrophorus Acetylcholinesterase

Bon¹,

Huet

Lemonnier³

et al. 1976

European Journal of Biochemistry

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Molecular weights for the series of six Electrophorus acetylcholinesterase forms have been determined either by the sedimentation‐diffusion equilibrium method or, particularly in the case of the very scarce G′ and G″ forms, from their Stokes radius and sedimentation coefficient values. Both methods are in excellent agreement. The results provide good evidence for the model previously proposed, G″, G′ and G containing one, two and four subunits, whereas A, C and D possess, in addition to respectively one, two and three tetrameric sets of such subunits, a structural element, the tail. Although the amino acid composition of ‘tailed’ and globular forms did not reveal any significant feature of this element, its mass, about 100000 daltons, could be deduced from a comparison of molecular weights for the two classes of acetylcholinesterase forms. This value is in close agreement with electron microscopic data. The tail is thought to consist of three 30000‐dalton strands.

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A hydrophobic form of the small-intestinal sucrase-isomaltase complex

Cited by 102 publications

References 28 publications

Identification of a Prepore Large-Complex Stage in the Mechanism of Action of Clostridium perfringens Enterotoxin

Identification of a Prepore Large-Complex Stage in the Mechanism of Action of Clostridium perfringens Enterotoxin

Fine Mapping of the N-Terminal Cytotoxicity Region of Clostridium perfringens Enterotoxin by Site-Directed Mutagenesis

Molecular Forms of Electrophorus Acetylcholinesterase

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