Effect of long-chain alkyl sulfate binding on circular dichroism and conformation of soybean trypsin inhibitor

The disorganization and helix formation process of "Kunitz" soybean trypsin inhibitor (STI) effected by sodium dodecyl sulfate binding was investigated by the circular dichroism (CD) probe. The binding isotherms of dodecyl sulfate to STI were determined at the ionic strength of 0.033, 0.12, and 0.25 at pH 7.3, 25 degrees C. The perturbation and disorganization of this nonhelical protein were observed at an early binding stage (v, the average molar ratio of bound detergent to STI, up to about 7 in the case of the isotherm at I = 0.12). The disappearance of a positive CD peak at 226 nm and appearance of a negative CD band at 239 nm took place at this step and were affected by the number of carbon atoms in the alkyl group of detergents. The transition of the polypeptide backbone into a more ordered conformation proceeded gradually during cooperative binding of dodecyl sulfate molecules. An abrupt increase of detergent binding occurred near the critical micelle concentration of the detergent. The helix formation was completed prior to this step (v =30, at I = 0.12).

Amino acid sequence of cytochrome c from rice

The amino acid sequence of cytochrome c purified from rice, Oryza sativa L., was determined. The complete amino acid sequence of rice cytochrome c is as follows: Ac-Ala-8-Ser-Phe-Ser-Glu-Ala-Pro-Pro-Gly1-Asn-Pro-Lys-Ala-Gly-Glu-Lys-Ile-Phe10-Lys-Thr-Lys-Cys-Ala-Glx-Cys-His-Thr-Val20-Asp-Lys-Gly-Ala-Gly-His-Lys-Glx-Gly-Pro30-Asx-Leu-Asx-Gly-Leu-Phe-Gly-Arg-Glx-Ser40-Gly-Thr-Thr-Pro-Gly-Tyr-Ser-Tyr-Ser-Thr50-Ala-Asp-Lys-Asn-Met-Ala-Val-Ile-Trp-Glx60-Glx-Asx-Thr-Leu-Tyr-Asp-Tyr-Leu-Leu-Asn70-Pro-TML-Lys-Tyr-Ile-Pro-Gly-Thr-Lys-Met80-Val-Phe-Pro-Gly-Leu-TML-Lys-Pro-Glx-Glx90-Arg-Ala-Asp-Leu-Ile-Ser-Tyr-Leu-Lys-Glu100-Ala-Thr-Ser (Ac = acetyl group, TML = epsilon-N-trimethyllsine). The primary structure of rice cytochrome c was found to be homologous with those of other plant cytochromes c reported so far; it possesses general features common to plant cytochromes c, and all the invariant residues characterized in dicotyledonous cytochromes c are also conserved in the sequence of rice cytochrome c, as well as those of other monocotyledonous cytochromes c. The distinctive features of rice cytochrome c are a high content of proline residues, their unique locations in the sequence and the presence of a serine residue at position 96.

Double-blind study of Naproxen in osteoarthritis of the knee joint

To determine the effectiveness of naproxen in the treatment of osteoarthritis of the knee joint, a double-blind cross-over study against placebo was carried out on 61 patients. Statistically significant positive therapeutic effects were observed, including analgesia, increased mobility, decrease in joint swelling and improvement in activities of daily living. Side effects were infrequent, mild and disappeared rapidly.

Purification, stabilization and characterization of nitrite reductase from barley roots

Nitrite reductase (NiR) isolated from barley (Hordeum vulgare L.) roots was stabilized in a buffer solution containing a sulfhydryl-reducing reagent and glycerol. The enzyme was purified 340fold by ammonium sulfate fractionation and chromatography on DEAE-Sephadex A-50, Sephadex G-200 and DEAE-cellulose. Purified NiR had a specific activity of 28 μmol NO2 (-) reduced min(-1) mg(-1) of protein. The purified preparation was reddishbrown having absorption maxima at 282, 388 and 577 nm. The barley-root enzyme was almost identical with spinach-leaf NiR with respect to molecular weight, isoelectric point, pH stability, pH optimum, affinity for substrate, behavior toward inhibitors. It is concluded that NiR is the same enzymatic entity regardless of its localization in photosynthetic or nonchlorophyllous tissues. The electron-transport system for NiR in root tissue is discussed in comparison with that in leaf tissue.