(1984). Thin Filament Proteins and Thin Filament-Linked Regulation of Vertebrate Muscle Contractio. Critical Reviews in Biochemistry: Vol. 16, No. 3, pp. 235-305.

Thin filament proteins and thin filament-linked regulation of vertebrate muscle contraction.

The diradical mechanism for 1,3-dipolar cycloadditions and related thermal pericyclic reactions

Synthetic studies on the inhibitory region of rabbit skeletal troponin I. Relationship of amino acid sequence to biological activity.

There is now a large body of evidence in support of the view that Ca2+ binding to the low affinity sites of TnC induces a movement of helices B and C away from helices A and D, thus opening a hydrophobic cavity, the site of interaction with TnI. Another site of similar structure is formed by the helical segments in the C-terminal domain. Both sites appear to interact with the inhibitory segment of TnI. Whereas the interactions at both sites are necessary for the full regulatory activity of TnC, the interaction at the C-terminal domain stabilizes the complex and that involving the N-terminal domain is directly linked to the release of inhibition. In the absence of Ca2+ the inhibitory region of TnI would preferentially bind to actin and on Ca2+ binding to sites I and II it would switch to the site in the N-terminal domain of TnC. Detachment of TnI from actin gives rise to further events in thin filament regulation.

Molecular mechanism of troponin-C function.

Homoaromaticity has been the subject of many investigations and continues to remain an extraordinarily rich area of chemistry. Quantitative experimental evaluation of the level of long range delocalization and assessment of interactions in molecules having two or more insulating atoms, together with various theoretical estimates of energies and geometries, are areas currently being examined. The primary intention of this review is to provide a critical up-to-date survey of relevant spectral and structural data, as well as an analysis of the many reactions believed to involve generation of homoaromatic ions. Extensively discussed are mono-,bis-, and trishomoaromatic systems arranged on the basis of their cationic, anionic, or uncharged nature. Presentation of these individualized segments is preceded by a brief analysis of homoaromatic overlap.

The Realities of Extended Homoaromaticity

cis-2-Cyclooctene-1,4-dione 1 is prepared starting from 1,3-cyclooctadiene. Photoirradiation of 1 in ether gives a [π2s+2a] dimer, while irradiations in the presence of cyclic dienes give trans- [2+4]cycloadducts. The intermediacy of trans-2-cyclooctene-1,4-dione is suggested.

Synthesis and photochemistry of 2-cyclooctene-1,4-dione

2,5,7‐Cyclooctatrien‐1,4‐dion

Synthesis of Di(7-Cycloheptatrienyl)Ketone

Title compound (3) was prepared by a new method from bicyclo[4.2.0]octa-3,7-diene-2,5-dione through Diels-Alder reaction with butadiene, bromination with NBS, and then dehydrobromination with triethylamine. Thermolysis of (3) at 500°C gave, unexpectedly, 5-hydroxyacenaphthenone by a novel rearrangement. The intermediacy of 2,3-benzocyclooctatriene-1,4-dione is proposed.

Yasutaka Kayama

Papers

Synthesis and photochemistry of 2-cyclooctene-1,4-dione

2,5,7‐Cyclooctatrien‐1,4‐dion

Synthesis of Di(7-Cycloheptatrienyl)Ketone

A new synthesis and thermal rearrangement of 3,4-benzobicyclo[4.2.0]octa-3,7-diene-2,5-dione

Synthesis of bicyclo[4.2.0]octa-3,7-diene-2,5-dione