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Takao Matsuzaki

Publications and source records attributed to Takao Matsuzaki.

5 recordsLinked to original sources
PubMed2004

Structure of human translin at 2.2 A resolution.

The structure of human translin at 2.2 A resolution is reported in space group C222(1). Translin forms a tetramer in the asymmetric unit. Although the monomer structure is almost the same as the crystal structure of murine translin in space group P2(1)2(1)2, the relative positions of the tetramers differ between the human and murine translins. This suggests that the multimerization of translin is flexible; the flexibility may be related to the binding to DNA/RNA.

Crystallization↗
PubMed2004

Structural insight into nucleotide recognition in tau-protein kinase I/glycogen synthase kinase 3 beta.

Human tau-protein kinase I (TPK I; also known as glycogen synthase kinase 3 beta; GSK3 beta) is a serine/threonine protein kinase that participates in Alzheimer's disease. Here, binary complex structures of full-length TPK I/GSK3 beta with the ATP analogues ADP and AMPPNP solved by the X-ray diffraction method at 2.1 and 1.8 A resolution, respectively, are reported. TPK I/GSK3 beta is composed of three domains: an N-terminal domain consisting of a closed beta-barrel structure, a C-terminal domain containing a 'kinase fold' structure and a small extra-domain subsequent to the C-terminal domain. The catalytic site is between the two major domains and has an ATP-analogue molecule in its ATP-binding site. The adenine ring is buried in the hydrophobic pocket and interacts specifically with the main-chain atoms of the hinge loop. The overall structure and substrate-binding residues are similar to those observed in other Ser/Thr protein kinases, while Arg141 (which is not conserved among other Ser/Thr protein kinases) is one of the key residues for specific ATP/ADP recognition by TPK I/GSK3 beta. No residues are phosphorylated, while the orientation of the activation loop in TPK I/GSK3 beta is similar to that in phosphorylated CDK2 and ERK2, suggesting that TPK I/GSK3 beta falls into a conformation that enables it to be constitutively active.

Adenosine Diphosphate↗
PubMed1996

A New Family of Indoaniline-Derived Calix[4]arenes: Synthesis and Optical Recognition Properties as a Chromogenic Receptor(1).

A new family of indoaniline-derived calix[4]arenes has been synthesized for the purpose of developing a new chromogenic receptor. A condensing reaction of calix[4]arene (1) with 4-(diethylamino)-2-methylaniline hydrochloride (2) in the presence of an oxidizing agent under alkaline conditions affords mono- (3), 1,2-bis- (4), 1,3-bis- (5), and tetrakisindoaniline-derived (6) calix[4]arenes after careful column chromatography. Compound 3 is crystallized from a CHCl(3)-MeOH solution, and the crystal structure was determined by X-ray analysis. The crystal is monoclinic, space group P2(1)/n, Z = 4, a = 19.507(6) Å, b = 18.591(6) Å, c = 8.524(2) Å, beta = 94.69(2) degrees. The final R value for 2406 reflections of F(o) > 3sigma(F(o)) is 0.085. A unique intramolecular hydrogen-bonding network involving the carbonyl oxygen of indoaniline for 3 implied that the quinone carbonyl group as an acceptor of the chromophore can easily be subjected to an electrostatic interaction in the lower rim. Indeed, 1,3-bis(indoaniline)-derived 2,4-bis((ethoxycarbonyl)methoxy)calix[4]arene 7, prepared by the reaction of 5 with ethyl bromoacetate in the presence of NaH, is capable of undergoing an efficient ion-dipole interaction between the binding cation and the two quinone carbonyl groups of the chromophores, so that a selective Ca(2+)-induced pronounced color change (wavelength change > 100 nm) occurs with an association constant on the order of 10(6) in 99% EtOH, making 7 of potential use as an optical sensor for Ca(2+) detection. The IR and NMR studies have indicated that Ca(2+) is encapsulated in the cavity made by the distally located OCH(2)CO(2) groups on the lower rim of the cone-shaped calix[4]arene segment. Interestingly, however, the shape of the cavity in which Ca(2+) has been encapsulated does not have a C(2) axis of symmetry, as inferred from the (1)H-(1)H COSY experiment. On the other hand, 1,2-bis(indoaniline)-derived analogue 8 shows no response with metal ions, which can be interpreted to mean the absence of a cavity for encapsulation on the lower rim.

Journal Article↗