Structure at the Hinge Region in Rabbit Immunoglobulin-G

Smyth, D S; Utsumi, S

doi:10.1038/216332a0

Cited by 153 publications

(63 citation statements)

References 14 publications

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“…The amount of light scattered from the zona suggested that the precipitation caused by the lectins was as intense in the presence of Fab antibodies as in their absence and it was similar to the precipitation observed with goat anti-rabbit IgG (Plate 2). Fab antibodies are mainly carbohydrate free, although TV-acetylglucosamine residues may be present in 40% of the population (Smyth & Utsumi, 1967). However, no increase in the intensity of precipitation was observed with WGA.…”

Section: Binding Ofplant Lectins To Zona Fragmentsmentioning

confidence: 89%

Probable asymmetry in the organization of components of the hamster zona pellucida

Ahuja¹,

Bolwell²

1983

Reproduction

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Section: Binding Ofplant Lectins To Zona Fragmentsmentioning

confidence: 89%

Probable asymmetry in the organization of components of the hamster zona pellucida

Ahuja¹,

Bolwell²

1983

Reproduction

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“…This result suggested that the interdomain region was critically important for the activity of the enzyme. Perhaps the interdomain region introduces flexibility into the structure, allowing the relevant parts of the enzyme to move around, much like the hinge region in immunoglobulins (40,41).…”

Section: Discussionmentioning

confidence: 99%

Quaternary structure of human fatty acid synthase by electron cryomicroscopy

Brink

Ludtke

Yang

et al. 2001

Proc. Natl. Acad. Sci. U.S.A.

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We present the first three-dimensional reconstruction of human fatty acid synthase obtained by electron cryomicroscopy and single-particle image processing. The structure shows that the synthase is composed of two monomers, arranged in an antiparallel orientation, which is consistent with biochemical data. The monomers are connected to each other at their middle by a bridge of density, a site proposed to be the combination of the interdomain regions of the two monomers. Each monomer subunit appears to be subdivided into three structural domains. With this reconstruction of the synthase, we propose a location for the enzyme's two fatty acid synthesis sites. O besity, a major health factor, is a measure of the fat deposited with adipose in consequence to food intake, fatty acid and triglyceride synthesis and oxidation, and energy homeostasis (1). Excess food provides not only the energy needs of the body but promotes the synthesis of fatty acids and triglycerides and storage of the latter in liver and adipose tissues. The de novo synthesis of fatty acids from acetyl-CoA and malonylCoA in the presence of the reducing substrate NADPH is catalyzed by the enzyme fatty acid synthase (FAS, ref. 2). Malonyl-CoA is the donor of the C 2 units required for chain elongation and is generated by acetyl-CoA carboxylase reactions, the rate-limiting step in the synthesis of fatty acids. In animal tissues including that of humans, FAS is a homodimer of a multifunctional protein (M r 272,000; refs. 2 and 3). Each subunit protein contains seven catalytic activities plus the acyl carrier protein (ACP). The organization of the catalytic activities along the polypeptide chain from the N to the C termini is as follows: ␤-ketoacyl synthase, acetyl͞malonyl transacylases, ␤-hydroxyacyl dehydratase, enoyl reductase, ␤-ketoacyl reductase, ACP, and thioesterase. Throughout the elongation process, the fatty acyl groups are linked as a thioester to the 4Ј-phosphopantetheinyl-SH, the prosthetic group of the ACP component of FAS. This prosthetic group is Ϸ20 Å long and is an essential flexible linker for the catalytic activities of FAS (3, 4). The organization of the partial activities, as mentioned above, is based on proteolytic mapping of the subunit and is confirmed by the predicted amino acid sequences based on the cloning and nucleotide sequences of the cDNA of the FAS component enzymes (2, 5-11). Moreover, the multifunctional human FAS and its subdomains were cloned and expressed in Escherichia coli; the recombinant proteins were catalytically active, and their orders on the FAS subunit were established (12, 13). Based on these studies, the component activities were grouped into three functional subdomains: domain I, containing ␤-ketoacyl synthase, acetyl͞malonyl transacylases, and ␤-hydroxyacyl dehydratase; domain II, containing enoyl reductase, ␤-ketoacyl reductase, and ACP; and domain III, containing thioesterase. Moreover, an intermediate polypeptide containing 640 amino acids, located between domains I and II and designated as the int...

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“…cleavage, while without NAGA, it is sensitive to proteolytic cleavage [80]. As mentioned, some lymphocytes express IgG-like components on their surface.…”

Section: The Locus For the Action O F Proteolytic Lb T Triggeringmentioning

confidence: 99%

“…One is found around the middle of the basic protein of myelin from the central nervous system (BP), and the other is found around the middle of the H chain of the IgG molecule and is part of what is called the hinge region [80] (fig. 2).…”

Section: The Locus For the Action O F Proteolytic Lb T Triggeringmentioning

confidence: 99%

A Theory of Lymphocyte Blast Transformation (LBT) and Malignant Change Based on Proteolytic Cleavage of a Trigger Peptide: the Detendomer

Kast¹

1974

Oncology

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Evidence is outlined associating proteolytic events with initiation of lymphocyte blast transformation (LBT) in both antigen-specific and nonspecific mitogen-induced stimulation. It is proposed that lymphocytes normally express the hinge region of the IgG molecule on their surface and that this peptide (pro – thr – cys – pro – pro – pro) approximately constitutes a trigger peptide or detendomer that, by virtue of its proteolytic cleavage, stimulates the cell to LBT and mitosis, the trigger becoming inoperative when NAGA is linked to the threonine. The concept is extended to the malignant cell, which would express a detendomer similar in amino acid sequence and function to the lymphocyte blast detendomer, and would be triggered in a similar way. Evidence for this is presented.

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Structure at the Hinge Region in Rabbit Immunoglobulin-G

Cited by 153 publications

References 14 publications

Probable asymmetry in the organization of components of the hamster zona pellucida

Probable asymmetry in the organization of components of the hamster zona pellucida

Quaternary structure of human fatty acid synthase by electron cryomicroscopy

A Theory of Lymphocyte Blast Transformation (LBT) and Malignant Change Based on Proteolytic Cleavage of a Trigger Peptide: the Detendomer

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