Enzyme secretion

CCK is found in the digestive tract and the central and peripheral nervous systems. In the brain, CCK coexists with DA. In the peripheral nervous system, the two principal physiological actions of CCK are stimulation of gaU. bladder contraction and pancreatic enzyme secretion. CCK also stimulates glucose and amino acid transport, protein and DNA synthesis, and pancreatic hormone secretion. In the CNS, CCK induces hypothermia, analgesia, hyperglycemia, stimulation of pituitary hormone release, and a decrease in exploratory behavior. The CCK family of neuropeptides has been impHcated in anxiety and panic disorders, psychoses, satiety, and gastric acid and pancreatic enzyme secretions. 

These results prompted us to examine the characteristics of the extracellular pectolytic enzymes secreted in medium supplemented with glucose and galactose. Figure 2 shows the profile of elution of pectolytic activities recovered from the flow-through of a DEAE-cellulose column chromatographed on a CMC-cellulose column. 

Pectinolytic enzymes secreted by the diploid K. marxianus have been partially purified and characterized [eg 2] but the results obtained were very variable, partially contradictory and paid little attention to the physiological aspects of PG secretion [3]. Commercial use and production of PG from K. marxianus has attracted considerable interest [4]. 

Evidence of pectic enzymes secreted by FORL species has been obtained (3). The total proteins of FORL subjected to isoelectric focusing were resolved into several bands widely distributed between pi 5.9 and 7.45. FORL (rj) presented one mayor band of activity with a pi of 7.0 however, FORL (r ) presented one characteristic and principal band at 7.45, slightly more basic than these reported by others authors (4). 

IV. PARASITISM. Lysis by hydrolytic enzymes excreted by microorganisms is a well-known feature of mycoparasitism. Chitinase and P-l,3 glucanase (laminarase) are particularly important enzymes secreted by fungal mycoparasites capable of degrading the fungal cell wall components, chitin, and P-1,3 glucan (131-134). 

Robertson, B.D., Bianco, A.E., McKerrow, J.H. and Maizels, R.M. (1989) Toxocara cams, proteolytic enzymes secreted by the infective larvae in vitro. Experimental Parasitology 69, 30-36. 

Kadurugamuwa JL, Beveridge TJ (1995) Virulence factors are released from Pseudomonas-aeruginosa in association with membrane-vesicles during normal growth and exposure to gentamicin - a novel mechanism of enzyme-secretion. J Bacteriol 177 3998-4008... 

Malabsorption of protein and fat occurs when the capacity for enzyme secretion is reduced by 90%. A minority of patients develop complications including pancreatic pseudocyst, abscess, and ascites or common bile duct obstruction leading to cholangitis or secondary biliary cirrhosis. 

Cholecystokinin CCKa (CCKj) Human cDNA Anorexia, gastrointestinal disorders, pancreatitis, satiety, diabetes, obesity, nociception, schizophrenia, Parkinson s disease, addiction, cancer Pancreatic enzyme secretion, potentiation of opiate analgesia, gallbladder contraction, gut motility, growth promoting effects on some tumors, dopamine release... 

For many enzymes, a plot of activity against pH gives a bell-shaped curve with a well-defined pH optimum (Figure 3.8). Most enzymes are adapted to function at the particular pH of their enviromnent and, since the cytosolic pH is about 7.1, most intracellular enzymes have a pH optimum about 7.0. In contrast, the normal pH in the stomach is around 2.0, and most enzymes secreted by cells in the stomach have very low pH optima (e.g. pepsin, whose pH optimum is 2.0). 

Cholecystokinin (CKK) Stimulates enzyme secretion from pancreas and contraction of gall bladder. 

Unlike fungal saponinases, little is known about hydrolytic enzymes secreted by phytopathogenic oomycetes or their role in pathogenicity [75, 76]. Although innate resistance is believed to be the main mechanism by which oomycetes avoid the toxicity of saponins (see above), some oomycetes have been found to produce saponin hydrolases [77], as well as other glycosyl hydrolases [76]. 

Saccharomyces cerevisiae Synthetic HRP C gene fused in-frame to pre-pro a-mating factor. Constitutive and inducible promoters tried. Low Low levels of h3rperglycosylated enzyme secreted yield approx. 50 xg liter" (71, 72). 

CCK, a 33 amino acid regulatory peptide hormone, regulates motility, pancreatic enzyme secretion, gastric emptying, and gastric acid... 

Smith, R. J., and Ignarrr), L. J. (1975). Bioregulation of lysosomal enzyme. secretion from human neutrophils Roles of cyclic GMP and calcium in stimulus-secretion coupling. Proc. Natl. Acad. Sci. U.S.A. 72, 108-112. 

S ATP + myosin hght chain <1-12> (<1, 2, 8> event in initiation of smooth-muscle contraction [5] <8> involved in regulation of actin-myosin contractile activity in adrenal medulla [7] <8> obhgatory step in development of active tension in smooth muscle [13] <5> involved in myosin phosphorylation and enzyme secretion [16] <2, 3, 5, 6, 8, 10, 11> involved in muscle contractility and motility of non-muscle cells [33] <2> inhibition of actin-myosin ineraction [36,37]) (Reversibihty 1-12 [1-33]) [1-33]... 

FIGURE 2-21 The pH optima of some enzymes. Pepsin is a digestive enzyme secreted into gastric juice trypsin, a digestive enzyme that acts in the small intestine alkaline phosphatase of bone tissue, a hydrolytic enzyme thought to aid in bone mineralization. 

Ribonuclease, another small globular protein (Mt 13,700), is an enzyme secreted by the pancreas into the small intestine, where it catalyzes the hydrolysis of certain bonds in the ribonucleic acids present in ingested... 

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