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Type III Collagen
Type III Collagen is a homotrimer, or a protein composed of three identical peptide chains (monomers), each called an alpha 1 chain of type III collagen. Formally, the monomers are called collagen type III, alpha-1 chain and in humans are encoded by the gene. Type III collagen is one of the fibrillar collagens whose proteins have a long, inflexible, triple-helical domain. Protein structure and function Type III collagen is synthesized by cells as a pre-procollagen. The signal peptide is cleaved off producing a procollagen molecule. Three identical type III procollagen chains come together at the carboxy-terminal ends, and the structure is stabilized by the formation of disulphide bonds. Each individual chain folds into left-handed helix and the three chains are then wrapped together into a right-handed superhelix, the triple helix. Prior to assembling the super-helix, each monomer is subjected to a number of post-translational modifications that occur while the monomer is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peptide
Peptides (, ) are short chains of amino acids linked by peptide bonds. Long chains of amino acids are called proteins. Chains of fewer than twenty amino acids are called oligopeptides, and include dipeptides, tripeptides, and tetrapeptides. A polypeptide is a longer, continuous, unbranched peptide chain. Hence, peptides fall under the broad chemical classes of biological polymers and oligomers, alongside nucleic acids, oligosaccharides, polysaccharides, and others. A polypeptide that contains more than approximately 50 amino acids is known as a protein. Proteins consist of one or more polypeptides arranged in a biologically functional way, often bound to ligands such as coenzymes and cofactors, or to another protein or other macromolecule such as DNA or RNA, or to complex macromolecular assemblies. Amino acids that have been incorporated into peptides are termed residues. A water molecule is released during formation of each amide bond.. All peptides except cyclic pep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxidative Deamination
Oxidative deamination is a form of deamination that generates α-keto acids and other oxidized products from amine-containing compounds, and occurs primarily in the liver. Oxidative deamination is stereospecific, meaning it contains different stereoisomers as reactants and products; this process is either catalyzed by L or D- amino acid oxidase and L-amino acid oxidase is present only in the liver and kidney. Oxidative deamination is an important step in the catabolism of amino acids, generating a more metabolizable form of the amino acid, and also generating ammonia as a toxic byproduct. The ammonia generated in this process can then be neutralized into urea via the urea cycle. Much of the oxidative deamination occurring in cells involves the amino acid glutamate, which can be oxidatively deaminated by the enzyme glutamate dehydrogenase (GDH), using NAD or NADP as a coenzyme. This reaction generates α-ketoglutarate (α-KG) and ammonia. Glutamate can then be regenerated from α-K ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Collagen
Collagen () is the main structural protein in the extracellular matrix found in the body's various connective tissues. As the main component of connective tissue, it is the most abundant protein in mammals, making up from 25% to 35% of the whole-body protein content. Collagen consists of amino acids bound together to form a triple helix of elongated fibril known as a collagen helix. It is mostly found in connective tissue such as cartilage, bones, tendons, ligaments, and skin. Depending upon the degree of mineralization, collagen tissues may be rigid (bone) or compliant (tendon) or have a gradient from rigid to compliant (cartilage). Collagen is also abundant in corneas, blood vessels, the gut, intervertebral discs, and the dentin in teeth. In muscle tissue, it serves as a major component of the endomysium. Collagen constitutes one to two percent of muscle tissue and accounts for 6% of the weight of the skeletal muscle tissue. The fibroblast is the most common cell that crea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polypeptide
Peptides (, ) are short chains of amino acids linked by peptide bonds. Long chains of amino acids are called proteins. Chains of fewer than twenty amino acids are called oligopeptides, and include dipeptides, tripeptides, and tetrapeptides. A polypeptide is a longer, continuous, unbranched peptide chain. Hence, peptides fall under the broad chemical classes of biological polymers and oligomers, alongside nucleic acids, oligosaccharides, polysaccharides, and others. A polypeptide that contains more than approximately 50 amino acids is known as a protein. Proteins consist of one or more polypeptides arranged in a biologically functional way, often bound to ligands such as coenzymes and cofactors, or to another protein or other macromolecule such as DNA or RNA, or to complex macromolecular assemblies. Amino acids that have been incorporated into peptides are termed residues. A water molecule is released during formation of each amide bond.. All peptides except cyclic peptides ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exon Skipping
In molecular biology, exon skipping is a form of RNA splicing used to cause cells to “skip” over faulty or misaligned sections (exons) of genetic code, leading to a truncated but still functional protein despite the genetic mutation. Mechanism Exon skipping is used to restore the reading frame within a gene. Genes are the genetic instructions for creating a protein, and are composed of introns and exons. Exons are the sections of DNA that contain the instruction set for generating a protein; they are interspersed with non-coding regions called introns. The introns are later removed before the protein is made, leaving only the coding exon regions. Splicing naturally occurs in pre-mRNA when introns are being removed to form mature-mRNA that consists solely of exons. Starting in the late 1990s, scientists realized they could take advantage of this naturally occurring cellular splicing to downplay genetic mutations into less harmful ones. The mechanism behind exon skipping is a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ehlers–Danlos Syndromes
Ehlers–Danlos syndromes (EDS) are a group of 13 genetic connective-tissue disorders in the current classification, with the latest type discovered in 2018. Symptoms include loose joints, joint pain, stretchy velvety skin, and abnormal scar formation. These may be noticed at birth or in early childhood. Complications may include aortic dissection, joint dislocations, scoliosis, chronic pain, or early osteoarthritis. EDS occurs due to variations of more than 19 genes that are present at birth. The specific gene affected determines the type of EDS. Some cases result from a new variation occurring during early development, while others are inherited in an autosomal dominant or recessive manner. Typically, these variations result in defects in the structure or processing of the protein collagen. Diagnosis is often based on symptoms and confirmed by genetic testing or skin biopsy, but people may initially be misdiagnosed with hypochondriasis, depression, or chronic fatigue synd ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Base Pair
A base pair (bp) is a fundamental unit of double-stranded nucleic acids consisting of two nucleobases bound to each other by hydrogen bonds. They form the building blocks of the DNA double helix and contribute to the folded structure of both DNA and RNA. Dictated by specific hydrogen bonding patterns, "Watson–Crick" (or "Watson–Crick–Franklin") base pairs (guanine–cytosine and adenine–thymine) allow the DNA helix to maintain a regular helical structure that is subtly dependent on its nucleotide sequence. The Complementarity (molecular biology), complementary nature of this based-paired structure provides a redundant copy of the genetic information encoded within each strand of DNA. The regular structure and data redundancy provided by the DNA double helix make DNA well suited to the storage of genetic information, while base-pairing between DNA and incoming nucleotides provides the mechanism through which DNA polymerase replicates DNA and RNA polymerase transcribes DNA in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exon
An exon is any part of a gene that will form a part of the final mature RNA produced by that gene after introns have been removed by RNA splicing. The term ''exon'' refers to both the DNA sequence within a gene and to the corresponding sequence in RNA transcripts. In RNA splicing, introns are removed and exons are covalently joined to one another as part of generating the mature RNA. Just as the entire set of genes for a species constitutes the genome, the entire set of exons constitutes the exome. History The term ''exon'' derives from the expressed region and was coined by American biochemist Walter Gilbert in 1978: "The notion of the cistron… must be replaced by that of a transcription unit containing regions which will be lost from the mature messengerwhich I suggest we call introns (for intragenic regions)alternating with regions which will be expressedexons." This definition was originally made for protein-coding transcripts that are spliced before being translated. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tropocollagen
Collagen () is the main structural protein in the extracellular matrix found in the body's various connective tissues. As the main component of connective tissue, it is the most abundant protein in mammals, making up from 25% to 35% of the whole-body protein content. Collagen consists of amino acids bound together to form a triple helix of elongated fibril known as a collagen helix. It is mostly found in connective tissue such as cartilage, bones, tendons, ligaments, and skin. Depending upon the degree of mineralization, collagen tissues may be rigid (bone) or compliant (tendon) or have a gradient from rigid to compliant (cartilage). Collagen is also abundant in corneas, blood vessels, the gut, intervertebral discs, and the dentin in teeth. In muscle tissue, it serves as a major component of the endomysium. Collagen constitutes one to two percent of muscle tissue and accounts for 6% of the weight of the skeletal muscle tissue. The fibroblast is the most common cell that creates ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lysyl Oxidase
Lysyl oxidase (LOX), also known as protein-lysine 6-oxidase, is an enzyme that, in humans, is encoded by the ''LOX'' gene. It catalyzes the conversion of lysine molecules into highly reactive aldehydes that form cross-links in extracellular matrix proteins. Its inhibition can cause osteolathyrism, but, at the same time, its upregulation by tumor cells may promote metastasis of the existing tumor, causing it to become malignant and cancerous. Structure In the yeast strain ''Pichia pastoris'', lysyl oxidase constitutes a homodimeric structure. Each monomer consists of an active site that includes a Cu(II) atom coordinated with three histidine residues as well as 2,4,5-trihydroxyphenalanine quinone (TPQ), a crucial cofactor. In humans, the LOX gene is located on chromosome 5 q23.3-31.2. The DNA sequence encodes a polypeptide of 417 amino acids, the first 21 residues of which constitute a signal peptide, with a weight of approximately 32 kDa. The carboxyterminus contains the act ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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