Phenylalanine dehydrogenase produced by Bacillus badius IAM 11059 was purified from the crude extract of B. badius to homogeneity, as judged by disc gel electrophoresis. The enzyme has an isoelectric point of 3.5 and a relative molecular mass, Mr, of 310000–360000. The enzyme is composed of identical subunits with an Mr 41000–42000. The substrate specificity of the enzyme in the oxidative deamination reaction was high for l‐phenylalanine, but rather low in the reductive amination reaction, with phenylpyruvate, p‐hydroxyphenylpyruvate, and 2‐oxohexanoate. The gene for the enzyme was cloned into Escherichia coli with plasmid pBR322 as a vector. The enzyme was expressed in high level in E. coli. The enzyme produced by E. coli transformant was purified to homogeneity and shown to be identical to that of B. badius IAM 11059 with respect to the specific activity, Mr, subunit structure and amino acid composition.

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The atmospheric chemistry of (CF3)2CHOCH3, a possible HCFC/HFC alternative, was studied using a smog chamber/FT-IR technique. OH radicals were prepared by the photolysis of ozone in a 200-Torr H2O/O3/O2 gas mixture held in an 11.5-dm3 temperature-controlled chamber. The rate constant, k1, for the reaction of (CF3)2CHOCH3 with OH radicals was determined to be (1.40 +/- 0.28) x 10(-12) exp[(-550 +/- 60)/T] cm3 molecule(-1) s(-1) by means of a relative rate method at 253-328 K. The value of k1 at 298 K was (2.25 +/- 0.04) x 10(-13) cm3 molecule(-1) s(-1). The random errors are reported with +/-2 standard deviations, and potential systematic errors of 15% could increase k(1). In considering OH-radical reactions, we estimated the tropospheric lifetime of (CF3)2CHOCH3 to be 2.0 months using the rate constant at 288 K. The degradation mechanism of (CF3)2CHOCH3 initiated by OH radicals was also investigated using FT-IR spectroscopy at 298 K. Products (CF3)2CHOC(O)H, CF3C(OH)2CF3, CF3C(O)OCH3, and COF(2) were identified and quantified. The branching ratio, k1a/k1b, was estimated to be 2.1:1 for reactions (CF3)2CHOCH3 + OH --> (CF3)2CHOCH2*+ H2O (k1a) and (CF3)2CHOCH3 + OH --> (CF3)2C*OCH3 + H2O (k1b).

Humanpro-urokinase CDNAwas isolated from the CDNAlibrary constructed from human kidney mRNAusing the dC/dG homopo.lymer tailing method and Okayama-Berg method with pBR322as a vector. Amature polypeptide starting with Ser was produced in Escherichia coli under the control of the tac promoter and the Shine-Dalgarno sequence of the catechol 2,3-oxygenase gene derived from Pseudomonas putida. By replacing the sequence coding for N-terminal eight amino acids of pro-urokinase with the synthetic DNAoligomer, the bacterial pro-urokinase had a molecular weight of 47,000 daltons and accounted for 15%of the insoluble fraction of E. coli proteins in induced cells. Its biological activity was restored by renaturing the bacterial product. The activity of bacterial pro-urokinase was 450 IU/ml culture. Plasminogen activators play a role in plasminogen dependent fibrinolysis in a controlling blood clot lysis system. Two types of