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M Golinski

Publications and source records attributed to M Golinski.

8 recordsLinked to original sources
PubMed1996

Planarity of nitro-substituted phenothiazines.

The structures of three nitro-substituted phenothiazines [1,3,4-trifluoro-2-nitrophenothiazine, 10-(4-chlorobutyl)-1,3,4-trifluoro-2-nitrophenothiazine and 10-(4-chlorobutyl)-3-nitrophenothiazine] have been determined. The first of these red compounds forms infinite stacks in the solid state, in which donor and acceptor regions of the approximately planar molecules alternate. The molecules of the other two compounds, which have folded, or 'butterfly', conformations in the solid state, do not form stacks, presumably because the bulky chlorobutyl substituents cannot be accommodated. The very dark color of solid 3-nitrophenothiazine suggests the presence of extended molecular stacks, but crystals suitable for a structure determination could not be obtained.

Crystallization↗
PubMed1995

Malignant hyperthermia: a review.

Malignant hyperthermia (MH) was first identified as an anesthetic-related patient syndrome with familial tendencies in 1960. It is defined as a chain reaction of abnormalities triggered in susceptible individuals by commonly used anesthetic agents, and is classified as a hypermetabolic disorder of skeletal muscle. It is believed that susceptible patients possess a genetic predisposition for the development of the disease. In an acute episode of MH, the anesthetic triggering agent appears to interfere with the calcium ion reentry into the sarcoplasmic reticulum after muscle contraction. This process involving the calcium ion is the basis for all the clinical symptoms observed.

Humans↗
PubMed1992

Prostaglandin photoaffinity probes: synthesis and binding affinity of C-18 substituted PGF2 alpha prostanoids bearing a perfluorinated aryl azide.

C-18 Phenoxy analogs of prostaglandin F2 alpha (PGF2 alpha) that possessed a perfluorinated aryl azide and an aryl iodide substituent were synthesized and evaluated as potential photoaffinity probes for PGF2 alpha. Prior studies indicated that only hydrophobic modifications in the omega-side chain of PGF2 alpha were compatible with high binding affinity, and this finding excluded the use of a hydroxyl-substituted C-18 phenoxy group as an activated aryl ring capable of radioiodination. Consequently, an alternate means of introducing the iodine substituent using an ipsosubstitution of a trimethylsilyl arene was developed. Although this strategy was successful from a synthetic perspective, the potential PGF2 alpha photoaffinity probe, (15S)-18-[3'-((4''-azido-2'',3'',5'',6''-tetrafluorophenyl)- methoxy) methyl-5'-iodophenoxy]-19,20-bisnorprostaglandin F2 alpha, exhibited only marginal competitive binding with [3H]-PGF2 alpha to ovine luteal cells and to plasma membranes of bovine corpora lutea. The hydrophobic but bulky C-18 substituent was presumably incompatible with effective receptor binding.

Affinity Labels↗
PubMed1992

Prostaglandin photoaffinity probes: synthesis and binding affinity of aryl azide-substituted C-1 esters of prostaglandin F2 alpha.

In seeking prostaglandin F2 alpha (PGF2 alpha) photoaffinity probes possessing both an efficient, photoactive cross-linking substituent and a radiolabel of high specific activity, the synthesis and binding affinity of PGF2 alpha C-1 esters in which the alcohol component possessed either an aryl azide or a perfluorinated aryl azide was investigated. These derivatives showed great promise due to their ability to compete for the binding of [3H]-PGF2 alpha in both a luteal membrane binding assay and in a whole luteal cell binding assay. Identification of the C-1 site in PGF2 alpha as a site for modification of the PGF2 alpha molecule with photoactive alcohol derivatives represented a logical step toward the goal of developing a useful PGF2 alpha photoaffinity probe.

Affinity Labels↗
PubMedDate not supplied

Synthesis, binding affinity, and cross-linking of monodentate photoactive phenothiazines to calmodulin.

Various photoactive phenothiazines were synthesized that possessed a 2-azido, 3-azido, 2-benzoyl, or 1,3,4-trifluoro-2-azido functionality in combination with various modifications of the N-alkyl side chain. These phenothiazines were evaluated for their ability to inhibit the calmodulin-mediated activation of phosphodiesterase (PDE). All were active in inhibiting the action of calmodulin (CaM), but those possessing either a 3-azido and a 4-(4-methyl-1-piperazinyl)butyl side chain or a 2-benzoyl group and 3-(dimethylamino)propyl side chain proved to be most active (I50 = 14 +/- 3 microM and 7 +/- 1 microM, respectively) when compared to the known inhibitor, chlorpromazine (CPZ, I50 = 30 microM). Calmodulin was photolabeled with ca. 35% efficiency in a light- and calcium-dependent fashion using a radiolabeled analog, 3-azido-10-(4-(4-[14C]methyl-1-piperazinyl)butyl)phenothiazine, of one of these compounds. Competition studies using this radiolabeled analog and CPZ were consistent with binding to one or both of the hydrophobic binding pockets of CaM.

Affinity Labels↗
PubMedDate not supplied

Synthesis and use of a biotinylated 3-azidophenothiazine to photolabel both amino- and carboxyl-terminal sites in calmodulin.

The biotinylated probe, 3-azido-10-(4-(4-biotinyl-1-piperazinyl)butyl)phenothiazine, was used to examine the phenothiazine binding domains in calmodulin (CaM) by photolabeling. This phenothiazine, synthesized from 3-azido-10-(4-(1-piperazinyl)butyl)phenothiazine and d-biotinyl tosylate, inhibited the CaM-mediated activation of phosphodiesterase (PDE) with an I50 of 12.5 (+/- 2.8) microM. Photolabeling of CaM produced covalent adducts in excellent yield (32%) in a light- and Ca2+-dependent manner. Studies performed over a range of drug concentrations suggested a 2:1 stoichiometry for the binding of the phenothiazine probe to CaM. Limited trypsin digestion and purification of the resulting fragments by either SDS-PAGE or HPLC provided two principal phenothiazine-containing peptides. Amino acid composition and sequence analyses performed on these two peptides established that both the N- and C-terminal domains in CaM, particularly the regions amino terminal to Ca2+-binding loops 1 and 3, were modified by the photoactivated phenothiazine derivative. These data, particularly for the C-terminal domain, are in excellent agreement with the X-ray structure analysis of a 1:1 CaM-trifluoperazine complex.

Affinity Labels↗
PubMedDate not supplied

Synthesis and binding affinity of bidentate phenothiazines with two different photoactive groups.

The development of targeted, bidentate photoaffinity reagents for mapping the interacting domains of calmodulin (CaM) with the enzymes that it regulates required the synthesis and evaluation of the binding affinity of various phenothiazines. These photoaffinity reagents would possess a photoactive 3-azidophenothiazine group for cross-linking the hydrophobic binding domain of CaM, a second photoactive benzophenone group that would be activated at a different wavelength than the 3-azidophenothiazine group, and a suitable radiolabel. Difficulties were encountered in identifying those structural features that would be compatible with the introduction of a benzophenone group, with the solubility of these benzophenone-substituted phenothiazines, and with the ability of these phenothiazines to inhibit the calmodulin-mediated activation of phosphodiesterase. Solutions to this problem involved the preparation of phenothiazines possessing a quaternary ammonium salt, a zwitterionic amino acid, or a carbohydrate moiety. The phenothiazines that possessed photoactive 3-azido and benzophenone groups and in which one of the piperazine nitrogens in the side chain was converted to a quaternary, N-methylammonium iodide inhibited the calmodulin-mediated activation of phosphodiesterase at a level comparable to that of chlorpromazine.

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