Carboxypeptidase H is also known as carboxypeptidase E or CPE. It is an enzyme that plays a role in the processing and activation of neuropeptides, which are small protein-like molecules that function as chemical messengers within the nervous system. Carboxypeptidase H/E is responsible for removing certain amino acids from the end of newly synthesized neuropeptides, allowing them to become biologically active. It is widely expressed in the brain and other tissues throughout the body.

Carboxypeptidases are a group of enzymes that catalyze the cleavage of peptide bonds at the carboxyl-terminal end of polypeptides or proteins. They specifically remove the last amino acid residue from the protein chain, provided that it has a free carboxyl group and is not blocked by another chemical group. Carboxypeptidases are classified into two main types based on their catalytic mechanism: serine carboxypeptidases and metallo-carboxypeptidases.

Serine carboxypeptidases, also known as chymotrypsin C or carboxypeptidase C, use a serine residue in their active site to catalyze the hydrolysis of peptide bonds. They are found in various organisms, including animals and bacteria.

Metallo-carboxypeptidases, on the other hand, require a metal ion (usually zinc) for their catalytic activity. They can be further divided into several subtypes based on their structure and substrate specificity. For example, carboxypeptidase A prefers to cleave hydrophobic amino acids from the carboxyl-terminal end of proteins, while carboxypeptidase B specifically removes basic residues (lysine or arginine).

Carboxypeptidases have important roles in various biological processes, such as protein maturation, digestion, and regulation of blood pressure. Dysregulation of these enzymes has been implicated in several diseases, including cancer, neurodegenerative disorders, and cardiovascular disease.

Mannoheptulose is a type of sugar that occurs naturally in some plants, including avocados and a few other fruits. Its chemical formula is C7H14O7, and it's a heptose (a monosaccharide or simple sugar with seven carbon atoms) with a mannose configuration.

In the context of medical definitions, mannoheptulose might be mentioned in relation to certain metabolic disorders or dietary considerations. For instance, some research has suggested that mannoheptulose may have an impact on insulin secretion and glucose metabolism, although its effects are not fully understood and it is not widely used in clinical practice.

It's worth noting that while mannoheptulose does occur naturally in some foods, it's not a common or well-known sugar, and it's not typically included as an added ingredient in processed foods. As with any sugar or sweetener, it's generally a good idea to consume it in moderation as part of a balanced diet.

Chromaffin granules are membrane-bound organelles found in the cytoplasm of chromaffin cells, which are a type of neuroendocrine cell. These cells are located in the adrenal medulla and some sympathetic ganglia and play a crucial role in the body's stress response.

Chromaffin granules contain a variety of substances, including catecholamines such as epinephrine (adrenaline) and norepinephrine (noradrenaline), as well as proteins and other molecules. When the chromaffin cell is stimulated, the granules fuse with the cell membrane and release their contents into the extracellular space, where they can bind to receptors on nearby cells and trigger a variety of physiological responses.

The name "chromaffin" comes from the fact that these granules contain enzymes that can react with chromium salts to produce a brown color, which is why they are also sometimes referred to as "black-brown granules."

Carboxypeptidase B is a type of enzyme that belongs to the peptidase family. It is also known as carboxypeptidase B1 or CpB. This enzyme plays a crucial role in the digestion of proteins by cleaving specific amino acids from the carboxyl-terminal end of polypeptides.

Carboxypeptidase B preferentially removes basic arginine and lysine residues from protein substrates, making it an essential enzyme in various physiological processes, including blood clotting, hormone processing, and neuropeptide metabolism. It is synthesized as an inactive zymogen, procarboxypeptidase B, which is converted to its active form upon proteolytic activation.

In addition to its physiological functions, carboxypeptidase B has applications in research and industry, such as protein sequencing, peptide synthesis, and food processing.

Carboxypeptidases A are a group of enzymes that play a role in the digestion of proteins. They are found in various organisms, including humans, and function to cleave specific amino acids from the carboxyl-terminal end of protein substrates. In humans, Carboxypeptidase A is primarily produced in the pancreas and secreted into the small intestine as an inactive zymogen called procarboxypeptidase A.

Procarboxypeptidase A is activated by trypsin, another proteolytic enzyme, to form Carboxypeptidase A1 and Carboxypeptidase A2. These enzymes have different substrate specificities, with Carboxypeptidase A1 preferentially cleaving aromatic amino acids such as phenylalanine and tyrosine, while Carboxypeptidase A2 cleaves basic amino acids such as arginine and lysine.

Carboxypeptidases A play a crucial role in the final stages of protein digestion by breaking down large peptides into smaller di- and tripeptides, which can then be absorbed by the intestinal epithelium and transported to other parts of the body for use as building blocks or energy sources.

Lysine carboxypeptidase is not a widely recognized or used medical term. However, in biochemistry, carboxypeptidases are enzymes that cleave peptide bonds at the carboxyl-terminal end of a protein or peptide. If there is a specific enzyme named "lysine carboxypeptidase," it would be an enzyme that selectively removes lysine residues from the carboxyl terminus of a protein or peptide.

There are several enzymes that can act as carboxypeptidases, and some of them have specificities for certain amino acids, such as arginine or lysine. These enzymes play important roles in various biological processes, including protein degradation, processing, and regulation.

It's worth noting that the term "lysine carboxypeptidase" may refer to different enzymes depending on the context, such as bacterial or mammalian enzymes, and they may have different properties and functions.

Cathepsin A is a lysosomal protein that belongs to the peptidase family. It plays a role in various biological processes, including protein degradation and activation, cell signaling, and inflammation. Cathepsin A has both endopeptidase and exopeptidase activities, which allow it to cleave and process a wide range of substrates.

In addition to its enzymatic functions, cathepsin A also plays a structural role in the formation and stability of the protective protein complex called the "serglycin-cathepsin A proteoglycan complex." This complex protects certain proteases from degradation and helps regulate their activity within the lysosome.

Deficiencies or mutations in cathepsin A have been linked to several diseases, including a rare genetic disorder called galactosialidosis, which is characterized by developmental delays, coarse facial features, and progressive neurological deterioration.