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Home >> Dictionary of Bioinformatics, Biochemistry, Biotechnology >> Creatome Kinase CK - Cross Exon Recognition Complex
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C-reactive protein (CRP)
A β-globulin so called because it reacts with the C-polysaccharide of Pneumococcus. CRP binds to bacterial polysaccharides or phospholipids released from damaged tissues followed by activation of the complement pathway. In response to inflammation, CRP initiated opsonisation, phagocytosis and lysis of invading organisms.
Plasma concentration of CRP, which is less than1 mg/dL, rises rapidly in response to acute infections. Excessively high levels are seen following myocardial infarction, infection, inflammation, surgery, stress, trauma and neoplastic transformation. Estimation of plasma CRP is useful in screening for organic diseases, detecting intercurrent infections and rejections of renal allografts.
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Creatine Kinase (CK)
An enzyme that catalyses the reversible phosphorylation of Creatine by ATP. The enzyme is present in large amounts in cardiac, skeletal and smooth muscle. Brain is the only nonmuscular tissue that contains high levels of CK. CK exists as a dimer. Three isoenzymes are found in human tissues, composed of two monomers, M (for muscle) and B (for brain). These are designated CK-1 (CK-BB), CK-2 (CK-MB) and CK-3 (CK-MM).
All the three isoenzymes are present in the cytosol. A fourth isoenzyme, CKMt is found between the inner and outer membranes of the mitochondria. Posttranslational modifications by the action of carboxypeptidases produce the CK-MM isoforms. Measurement of CK is very useful in the diagnosis of myocardial infarction. The enzyme activity starts to rise 4-6 h after the onset of chest pain, reaches a peak value between 24-48 h and remains elevated for 3-5 days.
An increase in CK-MM3: CK MM1 ratio (normal 1.0) is seen 2-5 h after the onset of chest pain which is earlier than the response shown by other enzymes. Plasma CK activity is elevated in muscular dystrophies and is very high during the early clinical stages of Duchenne muscular dystrophy with a tendancy to fall in the terminal stages of the diseases.
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Creatine phosphate
A high energy compound present in muscles. It is used to regenerate ATP.
Creatinine
The internal anhydride of Creatine and a waste product whose urinary excretion is related to the functioning muscle mass. The normal excretion is 1-2 g per day. It is more in men than in women.
Creatinine clearance
A glomerular function test. Clearance of endogenous substances such as creatinine is more convenient because it does not require administration of an exogenous substances such as inulin. The normal value for creatine clearances is 120 mL/minute, which is close to the GFR.
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Creatinine clearance does not vary with urine flow rates unlike urea.
When the GRF is normal, tubular secretion of creatinine does not influence creatinine clearance. However, when the GRF is low, creatinine does not influence creatinine clearance. However, when the GRF is low, creatinine clearance is significantly higher than the GRF. In addition, creatinine breakdown in the gut also makes a contribution. Furthermore, there are difficulties in accurate collection of a 24 h urine sample. Using creatinine clearance, it is not possible to distinguish between prerenal, renal and postrenal causes of renal failure.
Creatinine Coefficient
The sum of milligrams of creatinine and creatine nitrogen excreted per kg body weight. The normal value is 7-10 for men and 5-8 in women.
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Crick, Francis (1918-2004)
An English physicist who together with James Watson won the Noble Prize in 1962 for deducing the double helical structure of DNA.
Crigler-Najjar syndrome
A condition characterised by increased plasma bilirubin levels due to an inherited defect in hepatic conjugation of bilirubin. It is of two types type I, in which there is complete absence of UDP-glucuronyl transferease activity, is inherited as an autosomal recessive trait. The plasma bilirubin levels exceed 20 mg/dL (345 mmol/L) in untreated cases. Phenobarbital has no effect on inducing enzyme activity in these patients.
Type II, which has an autosomal dominant mode of inheritance, is characterised by a deficiency of UDP glucuronyl transferase and follows a more benign course than Type I.
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The genetic defect is suggested to involve the hepatic UDP-glucuronyl transferase that adds the second glucuronyl group to bilirubin monoglucuronide. The plasma bilirubin concentration does not exceed 20 mg/dL (345 mmol/L) and patients respond to Phenobarbital therapy.
Creatinine height index (CHI)
The ratio of the milligrams of creatine excreted in 24 hours to height used as a measure of the body muscle mass.
Cretinism
Severe hypothyroidism in children characterised by short stature, coarse features, sparse hair, dry skin, protruding tongue, and impaired physical and mental development. In older children, sexual maturation is retarded and puberty is delayed.
Creutzfeld-Jakob disease (CJD)
A very rare, but well characterised, severe, progressive prion disease seen in parts of North Africa and Slovakia. It is transmitted during corneal or dural transplantation, and by contaminated neurosurgical devices or growth hormone preparations and is associated with dementia. See prion diseases.
Creatine (methylguanidoacetate)
A nonprotein nitrogen necessary for muscle contraction. Synthesis of Creatine requires three amino acids glycine, arginine and methionine. Creatine is present in the urine of children and very little is excreted in adults. The excretion of Creatine is greater in women than in men. It is increases in pregnancy, starvation, diabetes mellitus, fever, hyperthyroidism and in muscular disorders such as myasthenia gravis and muscular dystrophy.
Cristae
The infoldings of the inner mitochondrial membrane.
Critical concentrations
The minimal concentration of subunits necessary for the formation of a polymer.
Critical dissolved oxygen concentration (Ccrit)
The concentrations of dissolved oxygen in a submerged culture with oxygen as a limiting substrate. The oxygen level in the air supply to a fermenter is maintained above is Ccrit.
Cro protein
A protein that interferes with the synthesis and function of the C repressor of bacteriophage l. The protein is essential for the lytic response after infecting a host cell.
Cross
1. In genetic studies, the mating of two individuals or populations. Also termed mating.
2. The site of recombination. While a single crossover requires one reciprocal breakage union event, two simultaneous reciprocal breakage and reunion events are required for a double crossover.
3. The reciprocal exchange of DNA between two DNA molecules or two chromosomes involving a breakage and reunion mechanism. Also called recombination, recombinant event.
Cross-exon recognition complex
A large complex of RNA-binding SR proteins and other components that plays a role in delineating exon in the premRNAs of higher eukaryotes to ensure correct RNA splicing.
Cross-flow filtration
An effective method for filtering thick fluids that prevents fouling (build-up of material on a filter that blocks the flow).
Cross hybridation
Base pairing of a single-stranded DNA sequence that is partially but not completely complementary to a single-stranded substrate. Usually, this involves hybridizing a DNA probe for a specific DNA sequence to the homologous sequences of a different species.
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