Creatine


Description of Method. Creatine is an organic acid found in muscle tissue that supplies energy for muscle contractions. One of its metabolic products is creatinine, which is excreted in urine. Because the concentration of creatinine in urine and serum is an important indication of renal function, rapid methods for its analysis are clinically important. In this method the rate of reaction between creatinine and picrate in an alkaline medium is used to determine the concentration of creatinine in urine. Under the conditions of the analysis, the reaction is first-order in picrate, creatinine, and hydroxide.  [c.632]

Clinical Analysis. A wide range of clinically important substances can be detected and quantitated using chemiluminescence or bioluminescence methods. Coupled enzyme assay protocols permit the measurement of kinase, dehydrogenase, and oxidases or the substrates of these enzymes as exemplified by reactions of glucose, creatine phosphate, and bile acid in the following  [c.275]

H2 02+luminol creatine phosphate + ADP  [c.275]

Enzymes, measured in clinical laboratories, for which kits are available include y-glutamyl transferase (GGT), alanine transferase [9000-86-6] (ALT), aldolase, a-amylase [9000-90-2] aspartate aminotransferase [9000-97-9], creatine kinase and its isoenzymes, galactose-l-phosphate uridyl transferase, Hpase, malate dehydrogenase [9001 -64-3], 5 -nucleotidase, phosphohexose isomerase, and pymvate kinase [9001-59-6]. One example is the measurement of aspartate aminotransferase, where the reaction is followed by monitoring the loss of NADH  [c.40]

Fig. 4. Requirements, substrates, and products of Mo-nitrogenase catalysis, where I is the MoFe protein II the Fe protein and Pi is inorganic phosphate. The generating system is composed of creatine phosphate and creatine phosphokinase to recycle the inhibitory MgADP produced during catalysis to Fig. 4. Requirements, substrates, and products of Mo-nitrogenase catalysis, where I is the MoFe protein II the Fe protein and Pi is inorganic phosphate. The generating system is composed of creatine phosphate and creatine phosphokinase to recycle the inhibitory MgADP produced during catalysis to
A good example of an affinity label for creatine kinase has been presented (35). This enzyme catalyzes the reversible transfer of a phosphoryl group from adenosine triphosphate [56-65-5] (17) to creatine [57-00-1] (18), leading to adenosine diphosphate [7584-99-8] (19) and phosphocreatine [67-07-2]  [c.324]

Description of Method. Creatine is an organic acid found in muscle tissue that supplies energy for muscle contractions. One of its metabolic products is creatinine, which is excreted in urine. Because the concentration of creatinine in urine and serum is an important indication of renal function, rapid methods for its analysis are clinically important. In this method the rate of reaction between creatinine and picrate in an alkaline medium is used to determine the concentration of creatinine in urine. Under the conditions of the analysis, the reaction is first-order in picrate, creatinine, and hydroxide.  [c.632]

Creatine (H2O) and creatinine see entries in Chapter 6.  [c.173]

NAPHTHALENE DERIVATIVES] (Vol 16) a-Napthol-creatine phosphate-diacetyl  [c.660]

The loss of NADH is followed for determination of the en2yme creatine kinase.  [c.39]

Detoxifica.tlon. Detoxification systems in the human body often involve reactions that utilize sulfur-containing compounds. For example, reactions in which sulfate esters of potentially toxic compounds are formed, rendering these less toxic or nontoxic, are common as are acetylation reactions involving acetyl—SCoA (45). Another important compound is. Vadenosylmethionine [29908-03-0] (SAM), the active form of methionine. SAM acts as a methylating agent, eg, in detoxification reactions such as the methylation of pyridine derivatives, and in the formation of choline (qv), creatine [60-27-5] carnitine [461-06-3] and epinephrine [329-65-7] (50).  [c.379]

G s-Sensing Enzyme Electrodes. Potentiometry and amperometry are the most common electrochemical techniques to employ enzyme electrodes. Potentiometric gas-sensing and ion-selective electrodes have been converted into enzyme electrodes and used in various analytical appHcations (53). The gas-sensing electrodes for carbon dioxide and ammonia are most frequendy converted to enzyme electrodes because of the lack of response to any dissolved ionic interferents. Decarboxylating or deaminating enzymes are immobilized to these gas-sensing electrodes so that the enzyme reaction product, CO2 or NH, is detected. These potentiometric immobilized enzyme sensors are highly selective and are used for the detection of urea, creatinine, uric acid, amino acids (qv), and nucleotides, as well as other compounds (50,53). Amperometric electrodes are generally coupled with oxidase or dehydrogenase enzymes. Oxidase enzymes can be immobilized on a Clark oxygen electrode and used to detect the amount of oxygen consumed in the enzyme reaction. For example, in the determination of creatinine in blood semm, the enzymes creatinine amidohydrolase, creatine amidinohydrolase, and sarcosine oxidase are coimmobilized on the polypropylene membrane of a Clark oxygen electrode (60). The enzymes catalyze the decomposition of creatinine with the consumption of oxygen, which is monitored by the Clark electrode. The oxidase enzymes can also be trapped on a platinum electrode and used to measure the amount of hydrogen peroxide produced in the enzyme reaction. For example, glucose oxidase [9001-37-0] covalentiy attached to platinum wire via glutaraldehyde [111-30-8] C Hg02, was used to determine glucose [50-99-7] levels by monitoring the amount of hydrogen  [c.103]

A/-(2,3-Epoxypropyl)-A/-amidinoglycine [70363-44-9] (21) was shown to be an affinity label of creatine kinase. Its mechanism of covalent bond formation is outlined as follows  [c.324]

Sodium creatine phosphate (4H2O) [922-32-7] M 327.1. See creatine phosphate di-Na salt on p. 523 in Chapter 6.  [c.468]

Creatine (HjO) (V-guanidino-V-methylglycine) [6020-87-7] M 131.1, m 303°, pK 2.63, pKj 14.3. Likely impurities are creatinine and other guanidino compounds. Crystd from water as monohydrate. Dried under vacuum over P2O5 to give anhydrous material.  [c.523]


See pages that mention the term Creatine : [c.114]    [c.114]    [c.114]    [c.114]    [c.115]    [c.306]    [c.307]    [c.352]    [c.544]    [c.863]    [c.430]    [c.258]    [c.258]    [c.258]    [c.259]    [c.259]    [c.259]    [c.259]    [c.24]    [c.275]    [c.275]    [c.39]    [c.39]    [c.40]    [c.40]    [c.40]    [c.40]    [c.40]    [c.87]    [c.392]    [c.392]    [c.392]    [c.78]    [c.430]    [c.523]   
See chapters in:

Practical organic chemistry  -> Creatine


Organic syntheses Acrolein (0) -- [ c.4 , c.15 ]

Practical organic chemistry (0) -- [ c.132 ]