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Lytic enzymes of mycoparasitic fungi of the genus Trichoderma, capable of suppressing several fungal phytopathogens that originate in air or soil, are reviewed. The topics analyzed include (1) regulation of production of chitinases, beta-1,3-glucanases, and proteases; (2) molecular and catalytic properties of purified enzymes; and (3) their in vitro ability to degrade cell walls and inhibit sporulation or germ-tube elongation in various phytopathogenic fungi. Among the results summarized are reports of cloning the expression of genes coding for certain lytic enzymes of Trichoderma spp. These genes are used for obtaining plant transgenes with increased resistance to fungal diseases and Trichoderma transformants that produce higher levels of one lytic enzyme (a chitinase or protease) and thereby exhibit a more pronounced ability to suppress phytopathogenic fungi.

The effects of ointment containing king crab (Paralithodes camtschatica) collagenase on intact skin, thermal, and pyonecrotic wounds were studied in rats by using hematological, biochemical, immunological, and morphological methods. The ointment for the skin and viscera was shown to be safe. It is highly effective in debriding the infected wounds. Different concentrations of collagenase were tested. The concentration of collagenase was recommended to be 0.2 mg/g ointment for use.

We studied the activity of lysosomal cathepsins B and D, neutral trypsin-like proteinase, and the content of trypsin inhibitors in the mammary glands of virgin, pregnant, and lactating rabbit females, as well as during the involution caused by lactostasis. The maximal activity of cathepsin D was found to occur in mammary glands under the condition of lactostasis. The activity of cathepsin B was practically identical in the mammary glands of virgin and pregnant animals and diminished during lactation. The activity of trypsin-like proteinase is low in the mammary glands of virgin animals, increases drastically during pregnancy, and diminishes during lactation. The content of trypsin inhibitors is maintained at a similar level in the mammary glands of virgin and pregnant animals and increases significantly during lactation. The caseinolytic activity of neutral proteinases has not been detected in the mammary glands of virgin rabbit females. At the lactation and involution stages, it is considerably lower than the activity of acidic proteinases and is possibly controlled by endogenous inhibitors.

Cathepsin D was purified from the lactating rabbit mammary gland by a rapid procedure, which included fractionation with (NH4)2SO4, acid precipitation, double affinity chromatography on pepstatin-Sepharose 4B and gel filtration on Sephadex G-100, resulting in approximately 360-fold purification of the enzyme over the homogenate and approximately 16% recovery. After isoelectric focusing, the enzyme dissociated into four (pI 5.8, 6.3, 6.5 and 7.2) multiple forms, but appeared homogeneous on polyacrylamide gel electrophoresis. Cathepsin D has a Mr of 45 kDa as determined by Sephadex G-100 column chromatography. On sodium dodecylsulfate/polyacrylamide gel electrophoresis the enzyme gave a single protein band, corresponding to Mr of 45 kDa. The amino acid composition of the enzyme is similar to that of cathepsins D from other tissues. A single N-terminal amino acid was glycine. Cathepsin D contains 6.4% carbohydrates consisting of mannose, galactose, fucose and glucosamine at a ratio of 3:9:2:2. Cathepsin D is inhibited by pepstatin with Ki of 2.5 X 10(-9) M and irreversibly by N-diazoacetyl-N'-2.4-dinitrophenyl-ethylene diamine. The enzyme hydrolyzes bovine hemoglobin with the maximal activity at pH 3.0 with Km = 10(-5) M and HLeu-Ser-Phe(NO2)-Nle-Ala-Leu-OMe with Km = 4 X 10(-5) M and Rcat = 0.95 s-1. The major cleavage sites were Leu15-Tyr16, Phe24-Phe25 and Phe25-Tyr26 during hydrolysis of the oxidized insulin B-chain by cathepsin D.