Rennin

Bulk Enzymes. Enzymes such as proteases, amylases, glucose isomerases, and rennin are used in food processing. Similarly proteases and Hpases are used in detergents. CeUulases and xylanases are used in the paper pulp industry. The genes for most of the enzymes used in the various commercial processes have been cloned and overexpressed. Rennin (chymosin) produced from E. coli and A. nigerhas been approved by FDA for use in the dairy industry. 

The volume of extracellular fluid is direcdy related to the Na" concentration which is closely controlled by the kidneys. Homeostatic control of Na" concentration depends on the hormone aldosterone. The kidney secretes a proteolytic enzyme, rennin, which is essential in the first of a series of reactions leading to aldosterone. In response to a decrease in plasma volume and Na" concentration, the secretion of rennin stimulates the production of aldosterone resulting in increased sodium retention and increased volume of extracellular fluid (51,55). 

Escherichia coli. The genetics of this gram-negative bacterium are very well known. For this reason, many of the first efforts to produce recombinant products from this microorganism were successful. However, because of the importance of the other criteria Hsted above, many efforts failed. E. co/i is only used to produce the milk-clotting mammalian protease chymosin [9001-98-3] (rennin). 

Although acid caseins are employed for a number of purposes, rennet caseins in which the protein remains associated with calcium and phosphate are preferred for plastics applications. Rennet is the dried extract of rennin, obtained from the inner lining of the fourth stomach of calves, and is a very powerful coagulant. As little as 0.2 parts per million are said to be sufficient to coagulate slightly acidic milk. Its coagulating power is destroyed at 100°C. 

The second enzyme to be crystallized (byjohn Nordrrnp in 1930). Even more than nrease before it, pepsin. study by Northrnp established tirat enzyme activity comes from proteins. fAiso known as rennin, it is tire major pepsinlike enzyine in gastric Jnice of fetal and newborn animals. 

Lab-essenz,/. rennet extract, rennet, -ferment, n. rennet ferment, rennin. labil, a. labile, unstable. 

The carboxyl proteases are so called because they have two catalytically essential aspartate residues. They were formerly called acid proteases because most of them are active at low pH. The best-known member of the family is pepsin, which has the distinction of being the first enzyme to be named (in 1825, by T. Schwann). Other members are chymosin (rennin) cathepsin D Rhizopus-pepsin (from Rhizopus chinensis) penicillinopepsin (from Penicillium janthinel-lum) the enzyme from Endothia parasitica and renin, which is involved in the regulation of blood pressure. These constitute a homologous family, and all have an Mr of about 35 000. The aspartyl proteases have been thrown into prominence by the discovery of a retroviral subfamily, including one from HIV that is the target of therapy for AIDS. These are homodimers of subunits of about 100 residues.156,157 All the aspartyl proteases contain the two essential aspartyl residues. Their reaction mechanism is the most obscure of all the proteases, and there are no simple chemical models for guidance. 

Renin-angiotensin system, 5 148, 158 Renin inhibitors, 5 158—159 Rennets, 10 296 Rennin, 12 64 Reocorin... 

Specialized cells, called the juxtaglomerular apparatus (JGA), within the renal cortex are able to detect a fall in blood pressure and respond by secreting a proteolytic enzyme called renin (not to be confused with rennin). The substrate for renin, a liver-derived peptide called angiotensinogen, circulates in the plasma. Renin removes two amino acids from the N-terminal to produce angiotensin I, which is itself a substrate for angiotensin-converting enzyme (ACE). ACE removes two more amino acids to produce angiotensin II. 

B2 family 11, aldosterone synthase cyto- to-rennin CTPllB ... 

CHROMIUM-NUCLEOTIDES CHROMOGENIC SUBSTRATE ABSORPTION SPECTROSCOPY FLUORESCENCE SPECTROSCOPY GHROMOPHORE GHYMASE GHYMOPAPAIN GHYMOSIN (or, RENNIN)... 

There is a hypothesis that irregularity of the rennin-angiotensin system lies at the base of etiology of all cases of essential hypertension. However, despite all of the apparent attractiveness of this theory, there is still not enough proof for it to be accepted as the single reason of elevated arterial blood pressure. 

Like captopril, enalapril selectively suppresses the rennin-angiotensin-aldosterone system, inhibits angiotensin-converting enzyme, and prevents conversion of angiotensin I into angiotensin 11. 

Effect of coffee on blood pressure and CA065 activity rennin-angiotensin-aldoster-one system and catecholamines concentration in patients with essential hypertension. Polski Merkuriusz CA066 Lekarski 1999 7(40) 159-163. 

The first company based upon applied biocatalysis also dates back to the 19 century. In 1874 Christian Hansen started a company in Copenhagen, Denmark. His company— named Christian Hansen s Laboratory to this day—was the first in the industrial market with a standardized enzyme preparation, rennet, for cheese making. Rennet, a mixture of chymosin (also called rennin) and pepsin, was and still is obtained by salt extraction of the fonrth stomach of suckling calves. 

III. Structural Studies of Rennin Complexed With Inhibitors... 

Even though casein micelles are remarkably stable in milk under normal conditions, they are quite susceptible to minor alterations in pH, ionic composition and to treatment with the enzyme rennin which cleaves the glycomacropeptide (GMP) portion of the k-... 

Limited digestion of globular soy proteins with rennin affords a modified protein preparation which retains a high molecular weight (47). Whipping quality, measured by foam volume and stability, was superior in comparison with native proteins. The limited rennin proteolysis of soy was identified as a key factor in functionality, since this modification conferred improved solubility. 

Visser, S., van Rooijen, P.J., Schattenkerk, C., and Kerling, K.E.T. (1976) Peptide substrates for chymosin (rennin). Kinetic studies with peptides of different chain length including parts of the sequence 101-112 of bovine K-casein. Biochim. Biophys. Acta, 438, 265-72. 

Cheese is a concentrated dairy food produced from milk curds that are separated from whey. The curds may be partially degraded by natural milk or microbial enzymes during ripening, as in cured cheeses, or they may be consumed fresh, as in uncured cheeses like cottage cheese. Most commonly, a bacterial culture with the aid of a coagulating enzyme like rennin is responsible for producing the initial curd. The... 

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