The Role of Rennin Enzyme in Milk

The Role of Rennin Enzyme in Milk

The Role of Rennin Enzyme in Milk

To understand the role of the Rennin enzyme in milk, one must know about the different types of the enzymatic protein chymosin. The different forms of chymosin include Fermentation-produced chymosin, recombinant chymosin, and casein. This article will look at how these different types of chymosin interact with the Rennin enzyme.

The Role of Rennin Enzyme in Milk


The chymosin and rennin enzymes in milk are the two most important digestive enzymes that curdle the liquid in ruminants such as cows. Humans don’t produce enzymes, so they use different ones to break down the milk’s proteins. The enzymes’ actions are similar to those of cheese curds. They are responsible for creating curdled milk in a variety of animals, including cows, goats, seals, and chicks.

What Are Allosteric Enzymes?

The two enzymes play essential roles in the nutrition of young mammals. In infants, chymosin converts milk from liquid to semi-solid and allows it to stay longer in the stomach. Rennin and chymosin secretion peaks during the first few days after birth but declines. The enzyme is replaced by pepsin as the main gastric protease. Similarly, in ruminants, the enzymes are secreted in the neonatal stomachs but are not found in humans. Chimps and humans have mutations that prevent them from secreting chymosin.

A proteolytic enzyme called chymosin is synthesized in the abomasum of ruminants and calves. It acts as a coagulant in milk. Several different aspartic proteases are involved in milk curdling. Rennin and pepsin may be retained in cheese in a proteolytically active form and may also play an essential role in ripening.

Both rennin and chymosin are important for cheesemaking. Their native substrate is K-casein. Chymosin cleaves the peptide bond between amino acid residues 105 and 106 of k-casein, resulting in calcium phosphate caseinate. Chymosin also breaks the link between hydrophilic and hydrophobic groups in casein, forming a 3D network that traps the aqueous phase of milk.

Recombinant chymosin

Chymosin is a milk protein found in calf’s milk. The commercial product differs from the native chymosin, including bioactivity. Transgenic sheep milk also contains a different form of chymosin. In addition, the recombinant enzyme called Maxiren is produced by yeast. This new form of chymosin is similar to the native form but has some crucial differences.

Bioengineered chymosin has been approved for use in foods by the Food and Drug Administration (FDA). The product is considered ‘generally recognized as safe,’ meaning it does not require pre-approval. In addition, bioengineered chymosin does not require special labeling or indication of the source. These attributes make it an ideal cheese enzyme. A Danisco employee confirmed that the gene used to make fermentation-produced chymosin was initially from a calf rennet. The recombinant enzyme in milk is now used in 70 percent of cheese in the U.S.

Chymosin self-activates at a pH of four to five. However, plant cytoplasm is slightly alkaline. Therefore, it needs to be stored in an environment of lower pH, such as the vacuole or the intercellular space. However, a study involving chymosin derived from tobacco leaves found that this enzyme exhibited milk-clotting activity. The crude extracts were not soluble in milk because the pH of these plant tissues was not within this range.

The two variants of chymosin have similar rheological and sensory characteristics. The two variants differ in the position of amino acid residues. The recombinant chymosin A variant has an aspartic acid residue instead of glycine in position 244, whereas the chymosin B variant has a glycine residue in position 244. Both recombinant chymosin has the same protein-binding properties as the calf-rennet-derived chymosin.

Fermentation-produced chymosin

Chymogen is an enzyme produced in the fermentation process of Aspergillus niger var. awamori and is genetically identical to calf chymosin B. It is responsible for calf rennet’s exact yield, texture, and flavor. It also helps recover fat and protein in cheese and is used in all types of industrial cheese.

The production strain of chymosin is grown in an aqueous solution containing carbohydrates, nitrogen, and various organic and inorganic compounds. Cell disruption releases the chymosin from the producing organism, resulting in solid prochymosin. Centrifugation is used to collect it. Its low price makes fermentation-produced chymosin an attractive alternative to animal rennet.

The amino acid residues 102-108 of k-casein fit in the cleft of the active site. The two variants are often confused, as they elute almost identically by chromatography. This fact may explain the confusion between the two proteins. However, the k-casein protein is the more important of the two. The chymosin A-type is a molecule with a higher molecular weight, while the amorphous type has a lower molecular weight.

A significant problem with conventional cheese production has led to development of a synthetic substitute for rennin. This enzyme is also produced by fungi, primarily responsible for producing chymosin. However, it is also produced by bacteria and yeasts. Milk is primarily composed of water and fat, and protein. The protein is divided into whey and casein fractions, with casein proteins forming the curd during cheese production.

The recombination of prochymosin in milk occurs through a process known as recombination. The chymosin gene from a cow is removed from its genome and introduced into a plasmid. This plasmid is then introduced into a microorganism and translated into an active protein. The result is a fermented protein that is similar to chymosin.

Casein interferes with the rennin enzyme.

The rennin enzyme is a critical part of the digestive process in young mammals. Rennin is an aspartic protease that cleaves the peptide bond between Phe105 and Met106 in k-casein in milk. By interfering with this enzyme, milk is curdled. It also hydrolyzes the milk proteins, thus making cheese.

The primary mechanism of casein’s interference with the rennin enzyme in milk is the presence of kappa casein, which clumps together with b-lactoglobulin and increases the clotting time. These interactions also prevent rennin from interacting with adenosine. In addition, the casein proteins become less soluble in hot water.

The bioactive peptides found in cow milk are not the same as those in goat milk. Goat milk contains a different structure peptide and is digested more efficiently than cow milk casein. While these peptides are similar to b-casein, they are very different. However, a recent study indicates that b-casein has antibacterial activity.

A recent study found that kappa casein interacts with the rennin enzyme in milk. This interaction makes kappa casein more susceptible to calcium precipitation. It also affects the ability of the rennin enzyme to stabilize micellar structures. These proteins may have other functions. But the question is, does the milk interfere with rennin?

The digestive process of milk proteins has been studied extensively. While many studies have been performed in vitro and with purified protein fractions, more work is needed to understand how actual dairy products disintegrate in the human digestive tract. Whey and casein proteins display distinct behaviors in the gastrointestinal tract, and the degree of disintegration varies with processing. Further, caseins have different interactions with the enzyme that regulates calcium absorption.

The rennin enzyme causes Gigantism and acromegaly.

Excess GH secretion is responsible for Gigantism and microglia. The renin enzyme in milk cleaves angiotensinogen (a precursor to angiotensin II), which is then converted into angiotensin I in the body. Rennin is an acid protease derived from the mucosa of the calf stomach and used to curdle milk and cheesemaking. However, a disorder called Addison’s disease is caused by the autoimmune destruction of gastric parietal cells. This fails in the cells to secrete intrinsic factor, which is required to absorb vitamin B12.

Leave a Reply

Your email address will not be published.


What is a Kinase Enzyme?

What is a Kinase Enzyme?

What is a Kinase Enzyme? If you’re looking for cancer treatment, one of your first questions might be, “What is a kinase enzyme?” It is an enzyme that adds phosphates to other molecules, making them active or inactive. Kinases are involved in several cell processes, and some cancer treatments target the kinases linked to the […]

several different types of glycoside hydrolase enzymes

Glycoside Hydrolase Enzyme

Glycoside Hydrolase Enzyme There are several different types of glycoside hydrolase enzymes. Glycoside hydrolases are grouped into ‘ clans according to their catalytic residues and tertiary structures.’ They share evolutionary ancestry and biochemical properties. The CAZy database contains updated descriptions for each glycoside hydrolase family. The Koshland mechanism describes two different reactions, but there are […]