John W. Simpson

Regulation of Gingival Collagenase: A Possible Role for a Mast Cell Factor

Summary Serum free media from rat gingival tissue cultures contained active collagenase which was inhibited by the addition of rat serum or fetal bovine serum. The inhibitory action of serum on gingival collagenase was blocked by the addition of mast cell extract. The mast cell factor was non-dialyzable and heat stable but was inactivated by exposure to 20% TCA. Neither heparin, histamine and 5-hydroxytryptamine nor extracts from a variety of other tissues could substitute for the mast cell factor in the activation of gingival collagenase. A mast cell factor may participate in the in vivo regulation of collagenase activity. The authors thank Mrs. L. J. Rider, Mr. M. M. Campbell, Mrs. D. Woodson and Mr. M. Hickerson for technical assistance.

Synthesis of a collagenase inhibitor by gingival fibroblasts in culture.

Human collagenase was inhibited by test solutions of human gingival fibroblast culture media. The fibroblast-derived collagenase inhibitor was only slightly affected by 10 micrograms trypsin but was inactivated with 100 micrograms trypsin. The chaotropic agent KSCN (3 M) completely inactivated the inhibitor, whereas the thiol-blocking reagent, p-aminophenylmercuric acetate, partially inactivated the inhibitor. Inhibitory activity was retained at 60 degrees C but was abolished at 100 degrees C. Following ammonium sulfate fractionation, the fibroblast inhibitor was recovered in the supernatant at concentrations of at least 70% saturation. It is suggested that collagenase latency in soft connective tissues may derive from a collagenase-inhibitor complex formed by interaction of collagenase and a fibroblast-derived inhibitor.

Distribution of elastase-like enzyme activity among snake venoms.

1. 1. Venoms from 25 poisonous snakes (12 Crotalidac, 5 Viperidac and 8 Elapidae) were studied for elastase-like enzyme activity. 2. 2. A correlation between elastase-like activities of venom and taxonomy of poisonous snakes at the family level was observed. All of the Crotalidae and Viperidae venoms but none of the Elapidae venom tested hydrolyzed the synthetic elastase substrate t-BOC-l-alanine-p-nitrophenol. 3. 3. No correlation between elastase-like activity and genera of poisonous snake was observed. 4. 4. HgCl2, cysteine, PMSF and EDTA markedly inhibited venom elastinolytic and p-nitrophenyl esterase activities.

Collagenolytic activity in some snake venoms

Abstract 1. 1. Venoms from the snakes Crotalus atrox, Agkistrodon contortrix contortrix, Agkistrodon piscivorus leukostoma and Bitis nasicornis contain an enzyme which is capable of reducing the specific viscosities of collagen solutions, but venom from Vipera russelli, Ophiophagus hannah and Naja naja apparently do not have this capability. 2. 2. Venom from bee Apis mellifera and spiders Aranea diadema and Lactrodectus mactans apparently do not have a collagenolytic enzyme. 3. 3. Crotalus atrox venom but not venom from Ophiophagus hannah is capable of digesting rat mesenteric native collagen fibers during tissue culture.

Elastolytic Activity from Venom of the Rattlesnake Crotalus atrox

Summary In vitro incubation of rat aorta with rattlesnake venom led to the destruction of the elastic fibers of the aorta. Correlated with this action, venom contained enzyme activity which solubilized Congo red-elastin and catalyzed the release of p-nitrophenol from the synthetic elastase substrate t-BOC-L-alanine p-nitrophenol. Therefore, rattlesnake venom contains an elastase-like enzyme.

Identification of Collagenase in Cultured Blood Mononuclear Cells

Mononuclear cells isolated from peripheral whole blood were fractionated by erythrocyte-rosetting into T cells and non-T cell subpopulations which were tested for collagenase-producing capacity. Mononuclear cells and purified T lymphocytes, as well as non-T (B) lymphocytes, produced collagenase during serum-free culture. Removal of the macrophages from the non-T cells did not affect collagenase production by lymphocytes.

Distribution of collagenolytic enzyme activity among snake venoms.

Abstract 1. 1. Venoms from twenty-six poisonous snakes (twelve Crotalidae, five Viperidae and nine Elapidae) were studied for collagenolytic enzyme activity. 2. 2. A correlation between collagenolytic activities of venom and taxonomy of poisonous snakes at the family level was observed. Viperidae venoms contained less collagenolytic activity than Crotalidae venoms while only three of nine Elapidae venoms contained minimal collagenolytic activity. 3. 3. No correlation between collagenolytic activity and genera of poisonous snakes was observed. 4. 4. Venom-catalyzed viscosity reduction of collagen solutions results from the degradation of collagen β components to altered α chains. Thus, the predominant collagenolytic enzyme mechanism of snake venoms is similar to the collagenolytic activities of chymotrypsin and pepsin.

Pathways for Glucose Metabolism in the Rat Gingiva: I. Patterns of Enzymes of Glucose Metabolism

The reported alterations in oxygen consumption in inflamed and proliferating human gingiva (GLICKMAN, TURESKY, and HILL, J Dent Res 28: 83-94, 1949; SCHRODER and SCHRODER, Helv Odontol Acta 1: 13-16, 1957; MANHOLD and VOLPE, J Dent Res 42:193-109, 1963) are highly suggestive of a disease-related shift to an alternate glucose metabolic pathway. The purpose of this paper is to identify the potentials of competing pathways for glucose metabolism in gingiva based on assays for 15 pertinent enzymes in rat gingival homogenates. Enzyme activities were measured in supernatants from rat gingival homogenates prepared as previously described. Determinations of the

Collagenolytic activity of snake venom: The effects of enzyme inhibitors on the collagenolytic and trypsin-like enzymes derived from Crotalus atrox venom

1. 1. Eleven enzyme inhibitors were tested for their effects on the collagenolytic and trypsin-like enzyme activities derived from Crotalus atrox venom. 2. 2. Venom collagenolytic enzyme activity was inhibited completely by potassium cyanide and EDTA and partially inhibited by cysteine. 3. 3. Venom trypsin-like enzyme activity was inhibited completely by diisopropylfluorophosphate, 87 per cent by diethyldithiocarbamate and 70 per cent by cysteine.

Collagenolytic activity of snake venom: The absence of collagenolytic activity in the trypsin-like enzyme from Crotalus atrox venom☆

Abstract 1. 1. Proteolytic activity in Crotalus atrox venom includes collagenolytic and trypsin-like enzymatic activities. Venom trypsin-like enzyme was purified free from collagenolytic activity by a pH step followed by electrofocusing. 2. 2. Venom trypsin-like enzyme prepared by electrofocusing neither caused a reduction in specific viscosity of collagen solutions nor catalyzed the degradation of the polypeptide chains of collagen. 3. 3. The results demonstrate that individual venom proteases are responsible for the trypsin-like and collagenolytic activity.