From some soil of Taipei, we isolated a strain of alkalophilic bacterium, Bacillus sp. HA3-3-2, that was capable of producing sufficient amounts of Cyclodextrin glucanotransferase (CGTase) in the culture broth. This enzyme was successively purified by ammonium sulfate fractionation, Sephadex column chromatography and DEAE-cellulose column chromatography. The final preparation thus obtained showed only a single band, when assayed by polyacrylamide disc gel electrophoresis and SDS-polyacrylamide gel electrophoresis. The molecular weight was estimated as 68, 000 by SDS-polyacrylamide gel electrophoresis. The purified enzyme possessed its maximum cyclodextrin-forming activity in the pH range of 6.5 to 8.0, and was stable between pH 6 and 11. This enzyme was not inhibited by typical bio-specific inhibitors, e.g., phenylmethylsulfonyl fluoride (PMSF), p-chloromercuribenzoate (PCMB) and ethylenediaminetetraacetic acid (EDTA).
On the basis of its properties, this enzyme seems to be a novel CGTase.

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The effect of bitter substances on the self-sustained electric oscillation of a DOPH (dioleyl phosphate)-Millipore membrane was investigated as a model system of taste reception. Caffeine and theobromine, having higher taste thresholds, had slight effect, but quinine, strychnine and nicotine, exhibiting strong bitterness, increased the frequency of the oscillation. The mode of action of bitter substances on the DOPH-Millipore membrane in the non-oscillatory state suggested that they cause the receptor potential by a change in the phase boundary potential. The intensity of action on the electric potential was associated with the threshold values of bitterness.

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Hairy root clones of Scopolia japonica were established by selection of adventitious roots formed on the root segments inoculated with Agrobacterium rhizogenes strain 15834. Twenty-nine isolated hairy root clones displayed various phenotypes characterized by growth rate, opine production and tropane alkaloid production. Of these, two highly alkaloid productive clones SI and S22 were examined for their growth rate and alkaloid productivity under various cultural conditions. When the most scopolamine-productive clone SI was cultured for 4 weeks at 25°C in the dark, the weight of the root tissue was increased by 40 times and the content of scopolamine reached a level of 0.5% on a dry weight basis in each optimum medium. On culture of the most hyoscyamine-productive clone S22 under the same conditions as with SI, the weight was increased by 102 times and the content of hyoscyamine was 1.3% on a dry weight basis in each optimum medium.

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We found a potent platelet aggregation inhibitor in the culture broth of Streptomyces strain M-193. The inhibitor was purified as white crystals and investigated; it was identified as Staurosporine. It strongly inhibited the platelet aggregation induced by collagen or ADP with IC₅₀ values of 3.4μM and 11.6μM, respectively. The inhibitor had no effect on thrombin-induced platelet aggregation or membrane stabilization against heat-induced hemolysis.

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maso-Diaminopimelate dehydrogenase (EC 1.4.1.16) was purified to homogeneity from Corynebacterium glutamicum ATCC 13032. The enzyme had a molecular weight of about 70, 000 and consisted of two subunits identical in molecular weight. The enzyme was highly specific for meso-2, 6-diaminopimelate. The pH optima for deamination and amination were about 9.8 and 7.9, respectively. The Michaelis constants were 3.1 mM for maso-2, 6-diaminopimelate, 0.12 mm for NADP⁺, 0.28 mM for L-2-amino-6-ketopimelate, 36 mM for ammonia, and 0.13 mM for NADPH. D and L isomers of 2, 6-diaminopimelate competitively inhibited the oxidative deamination of maso-2, 6-diaminopimelate. The enzyme was distributed in a wider range of bacterial species than reported previously [Misono et al., J. Bacterial., 137, 22 (1979)] when assayed by a sensitive formazan formation method.

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During the enzymatic degradation of sinigrin, the release of glucose and the formation of allyl isothiocyanate via subsequent cleavage of the aglucon were studied in the presence or absence of ferrous ion over apH range of 3.5-7.5. The liberation of glucose increased linearly with the time of enzymatic cleavage of sinigrin for the first 20 min at the pHs used, and no inhibition of glucose liberation was caused by ferrous ion at the concentration tried.
On the other hand, the effects of ferrous ion on the formation of isothiocyanate changed greatly with changes of pH of the reaction medium. At pH 4.5 and 5.5, formation of isothiocyanate was strongly inhibited by ferrous ion, while such an effect of ferrous ion was notably depressed at pH 6.5 and disappeared at pH 7.5. These results were also confirmed by gas chromatographic analysis of the volatile cleavage products of the glucosinolates prepared from the seed meal of hakuran (an artificial variety of Brassica napus). From these results, it was suggested that ferrous ion is not involved in the enzymatic liberation of glucose from glucosinolate but in the subsequent degradation of the aglucon.

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The effects of L-cysteine, reduced glutathione, dithiothreitol, cysteamine, thiobenzoate, thiomalate, and thiophenol on the enzymatic degradation of sinigrin were investigated in combination with ferrous ion at different pHs (5.0-7.5). Formation of allyl isothiocyanate was greatly inhibited by addition of both the thiol compounds and ferrous ion to the reaction medium at pH 5.0 or 6.5.
Combined effects of the thiol compounds and ferrous ion on the formation of volatile products was also studied by gas chromatography using a mixture of allyl, 3-butenyl, and 4-pentenyl glucosinolates (1:4:1) as substrate. It was confirmed that the greater part of the volatile components produced in the presence of both the thiol compounds and ferrous ion was allyl, 3-butenyl, and 4-pentenyl cyanides and their corresponding cyanoepithioalkanes, even though the reaction medium was adjusted to pH 6.5.
Similar results were obtained when silver sinigrate, an analogous model compound to the aglucon of sinigrin, was degraded by the addition of sodium chloride in the presence of both the thiol compounds and ferrous ion.
The results suggest that in combination with ferrous ion, such common thiol compounds as L-cysteine and glutathione may be concerned in the production of nitriles from glucosinolates in natural systems, and that the acceleration of nitrile formation is probably attributed to much more rapid desulfuration than the progress of Lessen rearrangement of aglucon.

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Glycine, glycylglycine, glycine methyl ester and glycine ethyl ester were found to be effective for the production and release of β-galactosidase by Escherichia coli. Addition of an appropriate concentration of glycine and glycylglycine to the culture increased total enzyme production 6 to 7-fold and extracellular enzyme production over 240-fold at 24 hr cultivation. The enzyme synthesis was stimulated even at the exponential period of growth, and 93% of enzyme was found in the culture fluid at 24 hr cultivation on addition of 1.2% glycine. A large amount of protein was also accumulated in the culture fluid. A micrograph showed glycine gave swollen and irregular cells, indicating that the cell surface was altered. Various amino acid analogues and some antibiotics had a small or no effect on the production and release of the enzyme as compared with glycine. Polypeptone or brain heart infusion was needed as a nitrogen source for efficient production of the enzyme.

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When Thiobacillus ferrooxidans AP19-3 that had been treated to remove iron from the cell surface was incubated aerobically with both elemental sulfur and o-phenanthroline, Fe³⁺ still present was reduced by the ferric-ion reducing (FIR) system of the cells. Ferrous ion chelated with o-phenanthroline was not be oxidized by iron oxidase, and leaked out into the reaction mixture. In the absence of o-phenanthroline, however, Fe²⁺ was not detected, suggesting that it was rapidly reoxidized by iron oxidase. Sulfur oxidation by this strain under aerobic conditions was strongly inhibited by o-phenanthroline, so Fe²⁺ was probably produced as an intermediate during the oxidation of elemental sulfur. Sulfur-grown cells that were cultured successively in a sulfur-salt medium always had high levels of iron-oxidizing activity. The strain could use Fe²⁺ produced earlier by the FIR system for growth. We concluded that when T. ferrooxidans AP19-3 grows on a sulfur-salt medium under aerobic conditions, the strain used a sulfur oxidation route not reported before that comprises both the FIR and iron-oxidizing systems.

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Sepharose gels with L-amino carboxylic acid residues as a ligand (L-adsorbent) or with D-amino carboxylic acid residues (D-adsorbent) were prepared and used in affinity Chromatography. Among enzymes involved in the metabolism of glutamic acid, a group of pyridoxal phosphate dependent enzymes such as aspartate aminotransferase, alanine aminotransferase, and glutamate decarboxylase had significant affinity for the L-adsorbent, while glutamate dehydrogenase (an NADP dependent enzyme) had no detectable affinity for either the L- or the D-adsorbent. The affinity chromatography with L-adsorbent was used for the purification of serine hydroxymethyltransferase; a pyridoxal phosphate dependent enzyme.

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We have determined the complete nucleotide sequence of the plasmid pAM 330 DNA which is derived from Brevibacterium lactofermentum ATCC 13869, using the dideoxy chain termination method. It contains 4448 base pairs (bp), corresponding to a molecular weight of 3.0 mega-daltons. Computer-aided analysis of the sequence revealed eight open reading frames (ORFs).Some of these ORFs showed the presence of a canonical promoter and Shine-Dalgarno (SD) sequence upstream from the initiation codon and a terminator sequence downstream from the stop codon.

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In a comparison of the crude enzyme secreted by the bacterium Erwinia carotovora PERM P-7576 with the corresponding purified overall endo-pectate lyase (endo-PATE) pi (isoelectric point)-isozymes on a basis of equal activity and constitution, the former was found to have higher maceration activity for biochemical pulping of caustic soda-presoaked mitsumata (Edgeworthia papyrifera Sieb. et Zucc) bast than the latter. These results indicate that some additional enzyme (s) other than endo-PATE are required for the maceration. Focusing on the maceration activity, the intensive purification of the crude enzyme was conducted and another maceration factor was successfully isolated, which was identified as endo-pectin lyase (endo-PNTE). The isolated endo-PNTE was found to have a molecular weight of 39, 000, pi of 8.2 and a specific activity of 7, 911 units/mg. The enzymatic maceration of this bast fiber was concluded to be due only to a concerted action of these two enzymes.

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The effects on cholesterolemia of dietary additions (1.2%) of methionine and cystine to a 20% casein diet were studied in both euthyroid and thiouracil-induced hypothyroid rats. The hypothyroid rats lapsed into endogenous hypercholesterolemia, which was due to an increase in the very-low-density lipoprotein plus low-density lipoprotein-cholesterol [(VLDL+LDL)-Ch] concentration with no change in the high-density lipoprotein-cholesterol (HDL-Ch) concentration. These lipoprotein changes in hypothyroid rats resulted in a marked (5-fold) increase in the atherogenic index [AI, (VLDL-LDL)-Ch/HDL-Ch] when compared to that of elutyroid rats. Methionine reduced the hypercholesterolemia in the hypothyroid state by suppressing the elevation in (VLDL + LDL)-Ch with no significant reduction in HDL-Ch, resulting in a notable fall of AI, while methionine showed no significant effect on cholesterolemia and AI in the euthyroid state. Cystine induced hypercholesterolemia due to a significant elevation of HDL-Ch in the euthyroid state, but the amino acid showed no significant effect on cholesterolemia and hence AI in the hypothyroid state. These results suggest that methionine overcomes changes in the parameters involved in Ch biodynamics that cause hypercholesterolemia in the hypothyroid state, whereas cystine counterbalances the parameter changes and results in diminution of its hypercholesterolemic effect in the hypothyroid state.

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The effects of cytokinins, a class of plant hormones, on cell proliferation and protein synthesis were studied in rat-derived L₆ myoblasts cultured in a serum-free medium. Of the three cytokinins tested, isopentenyladenine, zeatin and ribosylzeatin, isopentenyladenine (5μM) most stimulated the growth and DNA synthesis of the myoblasts, and it dose-dependently (0-10μM) enhanced the proliferation and DNA synthesis of the cells. Isopentenyladenine (5 and 10μM) increased protein synthesis to twice that of control (0μM). These results suggest that isopentenyladenine, a trace component in plant food and a plant hormone, can affect the metabolism of an animal cell line of myoblasts.

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Pancreatic enzyme secretion in response to intestinal stimuli was investigated in swine that had been fitted with pancreatic and duodenal cannulae under anesthesia. Secretin was infused intravenously to provide stable secretion of the pancreatic fluid during the experiments. The trypsin activity in the pancreatic juice collected was used as an index of the pancreatic response, because enzymes were secreted in parallel under the experiments. Duodenal infusion of milk whey protein or oleic acid stimulated pancreatic enzyme secretion in the swine as well as in the rats previously reported. Intestinal infusion of soybean trypsin inhibitor (SBTI) also markedly stimulated the pancreatic enzyme secretion. However, SBTI had no stimulatory effect when pancreatic juice was absent in the duodenum. When pancreatic juice was reinfused into the duodenum with SBTI, pancreatic enzyme secretion was considerably stimulated. The requirement for the presence of pancreatic juice for stimulation by SBTI can be explained by the hypothesis that the stimulatory factor which is prevented from hydrolysis by SBTI is involved in the pancreatic juice. Duodenal infusion of the fraction of molecular weight 6, 000±1, 000 in pancreatic juice stimulated pancreatic enzyme secretion. This fraction of the rat pancreatic juice included a peptide which may act as a mediator ('monitor peptide') of the signal for pancreatic enzyme secretion previously reported. These results suggests that the feedback regulation of pancreatic enzyme secretion also operates in swine, and that a factor in the pancreatic juice may play a physiological role at least in part for the underlying mechanism of feedback regulation as well as in rats.

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Potato and corn starch granules were crosslinked by epichlorohydrin to various extents (DC = 0.6 - 7.1). Most of these crosslinked starches retained a granular structure after autoclaving, though their crystalline structure had been lost. Using these starches as a carbon source for the cultivation of Bacillus circulans F-2, the digestion of starch granules, bacterial growth and production of amylase were investigated in comparison with those obtained with raw potato and corn starch granules. An increase in the DC of the starches decreased their degradation rate and bacterial growth. On the other hand, the amount of amylase produced increased with an increase in the DC of the added starches. CLP induced a larger amount of amylase than CLC of the same DC. CLP (DC = 4.0) induced 0.6U/ml of amylase, which is 1.8 times as much as that induced by raw potato starch. This, together with the fact that it is autoclavable, proved CLP to be a most excellent carbon source for the production of Bacillus circulans F-2 amylase.

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Three microorganisms that degrade creatinine and contain sarcosine oxidase were isolated from soil and identified to be Alcaligenes denitrificans subsp. denitrificans J9 and Arthrobacter spp. J5 and J11. The three soil isolates degraded creatinine only via creatine by inducibly formed creatinine amidohydrolase, creatine amidinohydrolase, and sarcosine oxidase when cultivated with creatinine as the main nitrogen source. Sarcosine dehydrogenase, creatinine deiminase, and N-carbamoylsarcosine amidohydrolase were not induced by creatinine. Other microorganisms that degrade creatinine all contain sarcosine dehydrogenase as the enzyme for sarcosine oxidation, so these isolates seem to be unique in having sarcosine oxidase involved in their processes of creatinine degradation. Sarcosine oxidase was purified from A. denitrificans subsp. denitrificans J9 and partially characterized.

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Although neither kappa-carrageenan nor locust-bean gum gelled alone, a mixed aqueous solution of the above gums gave a gel at the concentration of 0.6% total gums in a range of low temperatures. The solution also gelled even at the concentration of 0.4% total gums in the presence of 0.1 % KCl. The maximum dynamic modulus was obtained with a series of the samples composed of kappa-carrageenan and locust-bean gum in the mixing ratios of 1:1 and 3:1 at the concentration of 0.6 and 0.8% total gums at 0°C. The dynamic modulus of a mixed solution of kappa-carrageenan and locust-bean gum was not influenced by pH between pH 7.0 to 11.5, but decreased in the acidic range.
We concluded that intermolecular interactions, at low temperature, between kappacarrageenan and locust-bean gum may take place on the K⁺ -bridge of the former and the backbone of the latter molecule at low concentrations, but at high concentration of the gums, self-association of kappa-carrageenan molecules might also occurred.

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The glutamate racemase (EC 5.1.1.3) gene of a lactic acid bacterium, Pediococcus pentosaceus, was cloned into Escherichia coli C600 with a vector plasmid, pBR322. The requirement of L-glutamate for the growth of E. coli in the minimum medium containing D-glutamate and the formation of a red pigment in a coupled enzyme reaction mixture were used to select clones expressing glutamate racemase activity. Glutamate racemase overproduced as 0.3-2.0% of the total soluble proteins in a clone carrying the plasmid pICR221, 10.3 kb of DNA, was purified from cell extracts about 130-fold to homogeneity. The purified enzyme has a molecular weight of about 40, 000 and is a single polypeptide chain. Glutamate is the sole substrate for the enzyme. Unlike many other amino acid racemases, glutamate racemase is devoid of cofactors: there is no evidence for pyridoxal 5'-phosphate or FAD in the ultraviolet spectrum of the purified enzyme, and the enzyme is not inactivated by carbonyl reagents such as hydroxylamine and sodium borohydride.

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Two species of chrysomelid leaf beetles found in Brazil, Diabrotica speciosa and Cerotoma arcuata, are strongly attracted to the root of Ceratosanthes hilariana (Cucurbitaceae). Root extracts stimulate a compulsive feeding response. The major feeding stimulants isolated from these extracts were cucurbitacin B and its 23, 24-dihydro derivative.

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Dark hydrogen production by a newly isolated marine green alga, Chlamydomonas MGA 161 was studied. This alga was a halotolerant, not a halophilic type, and grew well in both natural and artificial seawater media. From an experiment with cycloheximide addition, it was found that the hydrogenase reaction in this alga was not a rate-limiting step of dark hydrogen evolution. Starch accumulation increased at a low NH₄Cl concentration (0.5mM), at a low temperature (20°C), or at a high NaCl concentration (7%). Hydrogen evolution was correlated with starch degradation rather than starch accumulation, and the molar yield of hydrogen from starch-glucose was very high, at about 2 (mol H₂/mol glucose). A comparison of the distribution pattern of fermentation products in various green algae, showed a unique fermentation pattern for Chlamydomonas MGA 161, with high hydrogen evolution but almost no formate.

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The Rsal fragment (750 base pairs) containing the entire early sporulation gene spo0F of Bacillus subtilis was inserted in the downstream region of the P_R promoter of the expression vector, pEBR-151. The recombinant plasmid thus obtained was introduced into Escherichia coli HB101 and the synthesis of the spo0F gene product was induced by a temperature shift up. After induction for 7 hr, a protein of molecular weight 14, 000 (14 K protein) was overproduced to about 9% of the total cellular protein. The 14K protein was purified to 94% purity by four steps of column chromatography. Deletion analysis and the sequence determination of the NH₂-terminal amino acid residues of the purified 14 K protein confirmed that the 14 K protein is the spo0F gene product.

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The toxic principle in mussels collected in France, Sweden, the Netherlands, and Spain that caused diarrhetic shellfish poisoning was identified to be okadaic acid by its chromatographic properties and spectral data.

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We sought optimum culture conditions for the production by Pseudomonas chlororaphis B23 of nitrile hydratase activity. Addition of ferric and ferrous ions and the use of methacrylamide as an inducer greatly enhanced nitrile hydratase formation. When P. chlororaphis B23 was cultivated for 26 hr at 25°C in a medium consisting of 1 g of sucrose, 0.5 g of methacrylamide, 0.2 g of L-cysteine, 0.2g of L-glutamate (Na), 0.2g of L-proline, 50mg of KH₂PO₄, 50mg of KH₂PO₄, 50mg of MgSO₄•7H₂O, and 1 mg of FeSO₄•7H₂O per 100ml of tap water with the pH controlled at pH 7.5 to 7.8, the enzyme activity in the culture broth was 900-times that previously reported.

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The components of the strong and favorable aroma obtained from roasted shrimp were investigated. The aroma concentrate of roasted shrimp was isolated by combining the dichloromethane extract and carbon dioxide distillation methods. The concentrate was fractionated into acidic, basic and neutral fractions. Each fraction was analyzed by combined gas chromatographymass spectrometry. Seventy-seven compounds were identified, among which isovaleric acid, alkyl pyrazines, isovaleramide, ketones and some sulfur-containing compounds were the main and characteristic constituents of the roasted shrimp aroma.
These constituents were compared with those of the volatiles of boiled shrimp, which was prepared by using simultaneous distillation and extraction methods in a modified Likens and Nickerson's apparatus.

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Pseudomonas strain BE-81, capable of growing significantly on benzene as a sole carbon source, was isolated from enrichment culture. Strain BE-81 is suggested to metabolize benzene by the oxidation system via benzene glycol as an intermediate, and to be suitable for the continuous production of catechol without addition or regeneration of NADH₂.
The catechol accumulating mutant, strain 136R-3, was developed from strain BE-81 by complete blockage of catechol catabolisms including the meta and ortho pathways, using double mutagenesis induced by NTG, and enrichment by non-selective growth with p-hydroxy-benzoate, suicide treatment with halogenated compounds and antibiotics lysises in the presence of benzene and benzoate.

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Two proteins of low molecular weight, which bind cadmium and are rich in cysteine were isolated from kidneys of the striped dolphin, Stenella coeruleoalba, and identified as metallothioneins I and II. The two isoforms closely resembled horse renal isometallothioneins both in chromatographic behaviors and chemical compositions. The molecular weights of performic acidoxidized proteins were estimated to be 6, 800. Twenty to 21 cysteine residues and about 6 g-atoms of heavy metals (Zn, Cd, Cu, and Hg) were present per mole of each isomer.

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Two new lanostane-type triterpenoids, ganoderiol A (1) and ganoderiol B (2) were isolated from the fruiting bodies of Ganoderma lucidum, together with known ganodermanontriol (3) and ganodermatriol (4). The compounds were identified as 5∝-lanosta-7, 9(ll)-dien-3β, 24, 25, 26-tetraol (1), 15a, 26, 27-trihydroxy-5α-lanosta-7, 9(11), 24-trien-3-one (2), 24, 25, 26-trihydroxy-5α-lanosta7, 9(1l)-dien-3-one (3) and 5α-lanosta-7, 9(11), 24-trien-3β, 26, 27-triol (4), respectively.

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β-Glucosidases I, II, and III were isolated from the culture filtrate of a Streptomyces sp. by ammonium sulfate fractionation, hydroxylapatite column chromatography, filtration on Bio-Gel P-100, and DE-52 column chromatography. β-Glucosidase III had a single active band on disc-gel electrophoresis. Its optimum pH and temperature for activity were 6.0 and 60°C, respectively. The isoelectric point and molecular weight of the enzyme were pH 4.5 and 45, 000, respectively. From an experiment using ¹⁴C-labeled glucose, gentiobiose seemed to be formed from laminaribiose as isomaltose is formed from maltose by fungal α-glucosidase. The enzyme showed transglucosylation and produced gentiobiose from β-gluco-disaccharides and 4-O-β-D-glucopyranosyl-D-mannopyranose (epicellobiose). The enzyme acted on phenolic β-D-glucosides to produce unknown transfer products.

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Peptidylarginine deiminase, which catalyzes the deimination of arginyl residues in protein, required Ca²⁺ as an essential cofactor and the half-maximal activity was attained at 40 - 60 μM Ca²⁺. Other divalent cations were practically inactive except for Sr²⁺, which was about 50% as active as Ca²⁺ when tested at lOmM. However, Sr²⁺ at less than the concentration of 100 μM had little or no activity. The direct Ca²⁺ -binding for the enzyme showed a sigmoidal curve with a transition midpoint of about 110μM, indicating that the binding is cooperative. Analysis of Hill plots of the data revealed that the enzyme binds 3mol of Ca²⁺ /mol of protein with an apparent dissociation constant of 110μM. A conformational change upon Ca²⁺ -binding was also described for the enzyme using UV-diiference spectra. The alteration could be attributed to an increased exposure of the aromatic residues to a more aqueous environment, as has been described for Ca²⁺- bindingproteins such as calmodulin. Phosphatidylserine enhanced the reaction velocity and concomitantly reduced the Ca²⁺ -requirement for the enzyme. These effects were stimulated by the addition of diacylglycerol. Diacylglycerol alone had little or no effect. On the other hand, calmodulin had no effect on the enzymatic activity over a wide range of Ca²⁺ concentrations. These suggest that the activity and Ca²⁺ -sensitivity of Peptidylarginine deiminase is increased at the cell membrane.

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A chloroform/methanol extract of a peptic digest of bovine K-casein had binding activity to opioid receptors of rat brain. The active peptide was isolated by reverse-phase liquid chromatography on ODS and CN columns. The structure of the peptide was Ser-Arg-Tyr-Pro-Ser-Tyr-OCH₃, which corresponds to the methyl ester of the 33 - 38th residues of κ-casein. The peptide was esterified during the extraction process, and the structure was confirmed by a chemical synthesis. The IC₅₀ value of the peptide in a radioreceptor assay in the presence of 1 HM [³H]naloxone was 15 μM. The peptide did not have opioid agonistic activities in any of the assay systems tested. In the guinea pig ileum and rabbit vas deferens preparations, however, the peptide antagonized with morphiceptin and dynorphin A-(1-13), respectively. The peptide did not antagonize with [Leu]enkephalin in the mouse vas deferens preparations. Therefore, the peptide was an antagonist selective for the μ- and κ-types of opioid receptors. The peptide was named casoxin.

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