Chain disorder

A number of proteins are known to pass through a transient intermediate state, the so-called molten globule state. The precise stmctural features of this state are not known, but appear to be compact, and contain most of the regular stmcture of the folded protein, yet have a large side-chain disorder (9). 

Multilayers of Diphosphates. One way to find surface reactions that may lead to the formation of SAMs is to look for reactions that result in an insoluble salt. This is the case for phosphate monolayers, based on their highly insoluble salts with tetravalent transition metal ions. In these salts, the phosphates form layer stmctures, one OH group sticking to either side. Thus, replacing the OH with an alkyl chain to form the alkyl phosphonic acid was expected to result in a bilayer stmcture with alkyl chains extending from both sides of the metal phosphate sheet (335). When zirconium (TV) is used the distance between next neighbor alkyl chains is - 0.53 nm, which forces either chain disorder or chain tilt so that VDW attractive interactions can be reestablished. 

Metabolic Myopathies Glycogen Storage Disease Disorders of Lipid Metabolism Respiratory Chain Disorders Mitochondrial DNA Abnormalities Myotonias, Periodic Paralyses, and Malignant Hyperpyrexia Myotonias... 

Mitochondria are unique organelles in that they contain their own DNA (mtDNA), which, in addition to ribosomal RN A (rRNA) and transfer RN A (tRNA)-coding sequences, also encodes 13 polypeptides which are components of complexes I, III, IV, and V (Anderson et al., 1981). This fact has important implications for both the genetics and the etiology of the respiratory chain disorders. Since mtDNA is maternally-inherited, a defect of a respiratory complex due to a mtDNA deletion would be expected to show a pattern of maternal transmission. However the situation is complicated by the fact that the majority of the polypeptide subunits of complexes I, III, IV, and V, and all subunits of complex II, are encoded by nuclear DNA. A defect in a nuclear-coded subunit of one of the respiratory complexes would be expected to show classic Mendelian inheritance. A further complication exists in that it is now established that some respiratory chain disorders result from defects of communication between nuclear and mitochondrial genomes (Zeviani et al., 1989). Since many mitochondrial proteins are synthesized in the cytosol and require a sophisticated system of posttranslational processing for transport and assembly, it is apparent that a diversity of genetic errors is to be expected. 

Table 1 Thermal and geometrical data of selected semiflexible polymers giving rise to thermotropic hexagonal mesophases or main-chain disordered crystalline phases (adapted from [11])... 

Defects of complex II. These have not been fully characterized in the few reported patients, and the diagnosis has often been based solely on a decrease of succinate-cytochrome c reductase activity (Fig. 42-3). However, partial complex II deficiency was documented in muscle and cultured fibroblasts from two sisters with clinical and neuroradiological evidence of Leigh s syndrome, and molecular genetic analysis showed that both patients were homozygous for a point mutation in the flavoprotein subunit of the complex [17]. This was the first documentation of a molecular defect in the nuclear genome associated with a respiratory chain disorder. 

Articaine has been implicated in an episode of weakness of the limb muscles, fatigue, and anorexia in a patient with a rare respiratory chain disorder due to a genetic defect in mitochondrial DNA (Kearn-Sayre Syndrome). 

By varying the hydrocarbon chain length, the relative importance of the chain disorder induced thermally and by penetration of C12E04 can be investigated further. 

L8. Leonard, I. V., and Schapira, A. V. H., Mitochondrial respiratory chain disorders II Neurode-generative disorders and nuclear gene defects. Lancet 355, 389-394 (2000). 

Several classes of inborn errors of metabolism in addition to inborn errors of urea synthesis can cause neonatal hyperammonemia. These include organic acidurias, fatty acid oxidation defects, amino acidopathies, and mitochondrial respiratory chain disorders. All of these disorders have a number of features in common. Labor and delivery tend to be normal, and there are no predisposing risk factors. Clinical features present after 24 h of life and are progressive. They are inherited, and thus a family history of previously affected children or neonatal deaths may be present. While most are inherited in an autosomally recessive manner, ornithine tran-scarbamoylase (OTC) deficiency is X linked, and a family history of affected males in the maternal pedigree is not uncommon. 

The effect is thought to arise from destabilization of the LC phase of the phospholipid, with a concurrent increase in chain disorder and consequent... 

---