• Microbiology and Biotechnology Letters
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• v.27 no.6
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• pp.458-465
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• 1999

Streptomyces luteogriseus KT-10 isolated from Korean farm soil produced a strong cathepsin B inhibitor. Optimal conditions for the cathepsin B inhibitor production by s. luteogriseus KT-10 were evaluated. The cathepsin B inhibitor was produced with maximal yield in the cultural condition of pH 7.0 and $25^{\circ}C$ for 4 days. Optimal medium for the cathepsin B inhibitor production was determined to be a medium containing 20g, peptone 3g, yeast extract 1g, K2HPO4 0.5g, MgSO4.7H2O 0.5g, NaNO3 0.5g, NaCl 0.5g per l. The cathepsin B inhibitor produced by S. luteogriseus KT-10 could also inhibit the other proteinases such as trypsin, papain, and cathepsin D.

• Microbiology and Biotechnology Letters
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• v.29 no.2
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• pp.84-89
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• 2001

Isolation and Characterization of Cathepsin B inhibitor Produced by Streptomyces luteogriseus KT-IO. Han, Kil~Hwan and Sang~Dal Kim*. Department of Applied Microbiology, Yeungnam Universit}/t Kyongsan 712749, Korea - The cathepsin B inhibitor produced by Streptomyces luteogriseus KT-IO was very stable in heat, acidic and alkaline conditions. The cathepsin B inhibitor was isolated from the extracted fraction of culture broth with butanol, methanol and chloroform subsequently, the inhibitor was purified with following several column chromatography sLlch as DEAE-Sephadex A-25, Sephadex G-15, silica gel 60, Sephadex LH-20, and preparative HPLC. The cathepsin B inhibitor showed positively to detective reaction of ninhydrine, 5% H2S04, iodine, but negatively to the reaction of Ehrlich's reagent, DNS, aniline. The molecular formular of cathepsin B inhibitor was elucidated by JR, lH and 13C-NMR, FAB mass and elemental analyzer. Consequently, it was identified as C4HlI04N6. The cathepsin B inhibitor had the mode of competitive inhibition with the reaction of cathepsin B.

• Microbiology and Biotechnology Letters
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• v.19 no.3
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• pp.296-302
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• 1991

Glucose isomerase producer, which produces 488 U/ml of glucose isomerase activity in 500 ml flask scale, was isolated among 666 isolates of Actinomycetes from pine forest soil samples. The isolate was identified as Streptomyces luteogriseus through the studies about morphology (spiral aerial mycelia), cell wall type (Type I), spore chains (spiral form), pigment formation (gray melanine pigment) & metabolism (sugar utilization etc). The optimum conditions of fermentation were determined in 500 ml flask scale. The enzyme production was reached maximum after 4 days at pH 6.0~8.0 and 27~$30^{\circ}C$ in the medium containing 1.5~3.0% of xylose; 0.5-0.8% of glucose; 0.1% of $MgSO_4.7H_20$; 0.05% of $CoCI_2-6H_20$; 7.5% of corn steep liquor.

• Journal of Microbiology and Biotechnology
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• v.7 no.5
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• pp.333-340
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• 1997

An actinomycetes, KT-10 isolated from ginseng field in Kyongpook, Korea was selected based on its ability to produce a lysosomal cathepsin B inhibitor. The inhibitor purified from the culture supernatant of the isolate KT-10 showed strong inhibitory effects against cathepsin B as well as against papain when the activities were measured using synthetic substrate, ${\alpha}$-N-benzyloxycarbonyl-L-Iysine p-nitrophenyl ester (CLN) or ${\alpha}$-N-benzoyl-D,L-arginine 2-naphthylamide (BANA). The isolate KT-10 was identified as a species of Streptomyces based on its morphological characteristics and chemotaxonomic data. The TAXON program of Ward was used to identify Streptomyces sp. KT-10 as a strain of Streptomyces luteogriseus belong to cluster 18 of the genus Streptomyces with a Willcox probability 0.999388. The cathepsin B inhibitor was presumed to a novel material composed of a polyhydroxylamine.

• Microbiology and Biotechnology Letters
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• v.19 no.4
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• pp.405-412
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• 1991

The enzymes were immobilized by treating the microbial cells in 0.05% chitosan and 0.28% glutaraldehyde solution. The activity of immobilized cell was about 535 IGIC/g. Glucose isomerase was purified by 6.5 times after homogenization using 60% $(NH_4)_2S0_4$ fractionation, DEAE-cellulose and Sephadex G-150 gel filtration. The molecular weight of enzyme was about 140,000 when it was measured by HPLC and the purified enzyme had only one band by electrophoresis. It showed good enzyme activity at pH 7.5 and $75^{\circ}C$. The optimum conditions for enzyme reactions were shifted to pH 7.0 and $80^{\circ}C$ when the enzyme was immobilized. The enzyme reaction was activated by the addition of 5~10 mM magnesium ion and the thermostability was improved by the addition of 0.25 mM cobalt ion. The enzyme activity was competitively inhibited by sugar alcohols.

• Microbiology and Biotechnology Letters
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• v.29 no.2
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• pp.90-95
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• 2001

Kinetic Analysis of Cathepsin B Inhibitor Using a Spectrophotometric Assay. Han, Kil-Hwan and SangDal Kim*. Department of Applied MicrobioJ0f5Yt Yeungnam UniversitYt Kyongsan 77 2-749, Korea - The KHS 10, C4Hl10~6 formula produced from Streptomyces luteogriseus KT-] 0 effectively inhibited a lysosomal cysteine proteinase, cathepsin B. It inhibited the enzyme activity of cathepsin B competitively when the N a-CBZ-Llysine p-nitrophenyl ester HC] (CLN) was used as a substrate. The inhibition const:mt (Ki) of KHS 1 0 for cathepsin B detennined by spectrophotometeric assay was 430 nM. The effective inhibition of cathepsin B was observed at $25^{\circ}C$ :md pH 6.0. The cathepsin B inhibitor, KHSlO needed a preincubation of cathepsin B with the inhibitor for over 5 min. The KHS 10 preserved over 80% inhibition activity even after heat-treatment at $100^{\circ}C$ for ] hr.