Tomisaburo Kakuno

SOLVENT EFFECTS ON TRIPLET-STATE BACTERIOCHLOROPHYLL A AS DETECTED BY TRANSIENT RAMAN SPECTROSCOPY AND THE ENVIRONMENT OF BACTERIOCHLOROPHYLL A IN THE LIGHT-HARVESTING COMPLEX OF RHODOBACTER SPHAEROIDES R26

The frequency of BChl that was bound to the light‐harvesting complex (LHC) of Rhodobacter sphaeroides R26 was found to be 1598 cm‐1, a result which suggests that a pair of BChl molecules form a dimer in the LHC in the T1 state.

Ultraviolet imaging densitometry of unstained gels for two-dimensional electrophoresis

A system suitable for ultraviolet imaging densitometry of two-dimensional electrophoretic gels that are unstained is described, together with its applications. A flying-spot densitometer linked with a personal computer was used for data acquisition, generation of mapping data, and image processing. Randomly distributed zones of proteins on two-dimensional gels were detected at 280 nm without being stained by two-dimensional scanning, and the densitometric value of each pixel (0.2 x 0.2 mm) was memorized by the computer, which generated a mapping pattern with density contours. The amount and densitometric value of cytochrome c had a linear relationship in the range of 2-200 micrograms. Zone locations of bovine liver proteins separated on two-dimensional gels were indicated on a map expressed in X-Y coordinates, and the pIs and molecular weights could be calculated from the map by use of pI and molecular weight markers on the same gel.

Preliminary crystallographic study of a ribulose-1,5-bisphosphate carboxylase-oxygenase from Chromatium vinosum

Crystals of a ribulose-1,5-bisphosphate carboxylase-oxygenase from Chromatium vinosum were obtained with the hanging-drop vapor diffusion technique, using polyethylene glycol 4000 as precipitant. The crystal belongs to the cubic system, space group I432, with unit cell dimension a = 245.9 A. An asymmetric unit includes one-quarter (L2S2, L: large subunit, S: small subunit) of a hexadecameric molecule (L8S8, 544,000 Mr), which is located on the crystallographic point symmetry 222 or 4. The crystal diffracts to at least 3.0 A resolution.

An open reading frame in the Rhodospirillum rubrum plasmid, pKY1, similar to algA, encoding the bifunctional enzyme hosphomannose isomerase-guanosine diphospho-d-mannose pyrophosphorylase (PMI-GMP)

The nucleotide sequence of a BglII fragment (3188 bp) from the plasmid pKY1 of Rhodospirillum rubrum was determined. A significant similarity was found between the amino acid sequences deduced from the nucleotide sequence of BglII fragment with that of algA, encoding the bifunctional enzyme with both the activities of phosphomannose isomerase and guanosine diphospho-D-mannose pyrophosphorylase of Pseudomonas aeruginosa.

Rapid degradation of cucumber cotyledon lipoxygenase

The lipoxygenase activity from cucumber cotyledons grown with their embryonic axis was separated into two fractions having M(r)s of 90,000 and 96,000, respectively, by hydrophobic chromatography. However, from de-embryonated cucumber cotyledons, only one form of lipoxygenase having a M(r) of 90,000 was purified. The three lipoxygenases could not be distinguished from each other either immunologically or by their enzymatic properties. Furthermore, peptide maps of the 90,000 and 96,000-lipoxygenases were identical. In a crude homogenate of cucumber cotyledons, the 96,000-lipoxygenase was rapidly degraded to the 90,000-form. Thus, it was inferred that the 90,000-lipoxygenase was probably the 96,000-form which had lost a peptide fragment of 6,000. It is suggested that there is a specific proteolytic activity for the degradation of 96,000-lipoxygenase. Estimation of changes in the proteolytic activity during seedling growth suggests that the activity at least partly contributes to the rapid in vivo degradation of cucumber cotyledon lipoxygenase.

Crosslinking of LHC II-Less Oxygen-Evolving PS II Complexes with Bifunctional Reagents with Different Chain Lengths

Photosystem II (PS II) reaction center consists of six major proteins, the 47 and 43 kDa proteins, which carry antenne chlorophyll, the D1 and D2 proteins and two apoproteins of cytochrome b559. In addition, three extrinsic proteins of 17, 23 and 33 kDa, which are associated with the lumenal surface of the thylakoid membranes, are needed for oxidation of water [1]. The 33 kDa protein is required to stabilize and maintain the functional conformation of the Mn cluster [2,3], whereas the 23 and 17 kDa proteins have regulatory roles in oxygen evolution [4,5]. Reconstitution experiments suggests that the three extrinsic proteins are organised into a discrete complex [6,7].

Purification of acetylcholine receptor-like protein from fetal calf thymus.

Abstract: A cobrotoxin binding protein from the fetal calf thymus was isolated by affinity chromatography after solubilization with sodium cholate. The specific activity as a nicotinic acetylcholine receptor (AChR) was determined by assessing the bindingto [3H]‐α‐bungarotoxin (BuTx), using the high‐pressure liquid chromatography. An AChR‐like protein was detected in the amount of 1.39–2.14 nmol per g protein. The first peak of 420k‐protein from gel filtration of the eluate of affinity chromatography on aSephacryl column showed one major polypeptide band with an Mr of 40k, by polyacrylamide gel electrophoresis in sodium dodecylsulfate, two major protein bands with pi 5.4–5.6 and9.2 by isoelectric focusing, and reacted with sera from patients with myasthenia gravis.

Purification and partial characterization of two types of growth-inhibitory protein latently present in rabbit serum

Normal rabbit serum contained two kinds of growth-inhibitory protein, GI-I and GI-II, in latent forms. These latent inhibitors were activated by incubation at 37 degrees C for 12 h, and their activation was lowered by inhibitors for serine, cysteine and metalloproteinases. Both growth inhibitors were highly purified in active forms by successive column chromatographies. GI-I showed a major protein band with an Mr of 18,000 on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, while GI-II showed a major protein band with an Mr of 36,000. GI-I and GI-II half-inhibited the growth of rat tumorigenic cell line (RSV-BRL) at concentrations of 0.5 ng/ml and 10 ng/ml, excess concentrations. Of the 15 cell lines tested, GI-I specifically inhibited the growth of rodent and lagomorph cells, whereas GI-II nonspecifically inhibited the growth of all cell lines tested. Specificities for cell type and malignancy were not observed with either inhibitor. These growth inhibitors were stable to a reducing reagent and proteinase inhibitors, but labile to urea, acid, organic solvents, trypsin, plasmin and heating at 95 degrees C for 5 min. These properties suggested that both growth inhibitors might be distinct from known growth-inhibitory factors.

Structural Comparison Between Rhodospirillum Rubrum Plasmid and Chloroplast DNA

Plasmids in photosynthetic bacteria have been isolated from Rhodospirillum rubrum, Rhodobacter sphaeroides and Rhodobacter capsulatus (1–5). The sizes of their Plasmids ranges from 40 to 200 kilobases. Kuhl et al. (3) have isolated the identical plasmids from nine strains of R. rubrum. In addition, they have reported that the plasmid-less mutants show different colors from the wild strain and can not grow photosynthetically in the light (6). In order to elucidate the biological roles of the Plasmids in photosynthetic bacteria, it is essential to determine their DNA sequences. The present study reports the restriction map and the partial nucleotide sequences of R. rubrum Plasmid.