| methyl | <chemistry> Specific reference to the methyl group is made when macromolecules are modified after synthesis by enzymic addition of methyl groups. The group is transferred to nucleic acids and proteins. See: methyl transferase and DNA methylation. (18 Nov 1997) |
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| methyl accepting chemotaxis protein | Methyl accepting chemotaxis proteins. Proteins of the inner cytoplasmic face of the bacterial plasma membane with which the receptors of the outer face interact. Four different MCPs are known in E. Coli, each with a separate set of receptors. Can be methylated at various sites, methylation is part of the adaptation to the signal. Although important intermediate signal integration sites, they are not directly connected to the motor. (18 Nov 1997) |
| methyl aldehyde | <chemical> Commonly used fixative and antibacterial agent. As a fixative it is cheap and tends to cause less denaturation of proteins than does glutaraldehyde, particularly if used in a well buffered solution (buffered formalin, formal saline). Old formaldehyde solutions usually contain cross linking contaminants and it is therefore often preferable to used a formaldehyde generating agent such as paraformaldehyde. Formalin fumes, particularly in conjunction with hydrochloric acid vapour, are potently carcinogenic. (20 Jun 2000) |
| methyl blue | A sulfonated triphenylrosaniline dye used as a stain for cytoplasm, collagen, and Negri bodies, and as an antiseptic. (05 Mar 2000) |
| methyl bromide | <chemical> A volatile, toxic, colourless gas or liquid that is frequently used as a fumigant, it is similar in structure to chloroform. It is known to be a powerful ozone-destroying chemical, but it is broken down by some bacteria, thereis much scientific debate on how much danger methyl bromide poses to the ozone layer. (09 Oct 1997) |
| methyl-CCNU | A nitrosourea antineoplastic agent resembling carmustine (BCNU) and lomustine (CCNU). Synonym: semustine. (05 Mar 2000) |
| methyl chloride | <chemical> A hydrocarbon used as an industrial solvent. It has been used as an aerosal propellent, as a refrigerant and as a local anaesthetic. Chemical name: Methane, chloro- (12 Dec 1998) |
| methyl chloride transferase | <enzyme> S-adenosylmethionine is methyl donor to chloride, bromide or iodide ions Registry number: EC 2.1.1.- (26 Jun 1999) |
| methyl coenzyme M methylreductase | <enzyme> Crude extracts of methanospirillum hungatii Registry number: EC 1.- Synonym: methylreductase, methyl com methylreductase (26 Jun 1999) |
| methyl coenzyme M reductase | <enzyme> Proposed EC 1.12.99.2 Registry number: EC 1.12.- Synonym: methyl com reductase, mcri gene product (26 Jun 1999) |
| methyl cysteine hydrochloride | Mecysteine hydrochloride;the methyl ester of cysteine hydrochloride; a mucolytic agent. (05 Mar 2000) |
| methyl ethers | A group of compounds that contain the general formula r-och3. (12 Dec 1998) |
| methyl green | <chemical> Used as a biological stain and for the dyeing and printing of textiles. Usually compounded with zinc chloride. Pharmacological action: rosaniline dyes. Chemical name: Benzenaminium, 4-((4-(dimethylamino)phenyl)(4-(dimethyliminio)-2,5-cyclohexadien-1-ylidene)methyl)-N,N,N-trimethyl-, dichloride (12 Dec 1998) |
| methyl green-pyronin stain | <technique> A staining method useful for identification of plasma cells which are intensely pyroninophilic; a mixture of a green and a red dye that has the property of staining highly polymerised nucleic acid (DNA) green and low molecular weight nucleic acids (RNA) red. See: Unna-Pappenheim stain. (05 Mar 2000) |
| methyl group | A -CH3 group on a larger molecule. A carbon which is single-bonded to three hydrogens, and has one free bond to the rest of the molecule. (09 Oct 1997) |