The mitochondrial small heat-shock protein protects NADH:ubiquinone oxidoreductase of the electron transport chain during heat stress in plants

Functional inactivation of the mitochondrial small heat-shock protein (lmw Hsp) in submitochondrial vesicles using protein-specific antibodies indicated that this protein protects NADH:ubiquinone oxidoreductase (complex I), and consequently electron transport from complex I to cytochrome c:O₂ oxidoreductase (complex IV). Lmw Hsp function completely accounted for heat acclimation of complex I electron transport in pre-heat-stressed plants. Addition of purified lmw Hsp to submitochondrial vesicles lacking this Hsp increased complex I electron transport rates 100% in submitochondrial vesicles assayed at high temperatures. These results indicate that production of the mitochondrial lmw Hsp is an important adaptation to heat stress in plants.     

Intrageneric amplification of horse microsatellite markers with emphasis on the Przewalski's horse (E. pmewalskii)

Primer sequences flanking 13 microsatellite loci isolated from the domestic horse (E. caballus) were successfully used to amplify homologous loci in the Przewalski's horse (E. przewalskii). The results demonstrate that the level of polymorphism at all 13 loci in the Przewalski's horse was comparable to that in the domestic horse and the overall exclusion probability in the Przewalski's horse was calculated to be 0.9994. The results suggest that it should be possible to use E. caballus-derived microsatellite markers to provide parentage verification and additional valuable information to the captive management of E. przewalskii. The ability to amplify corresponding loci in the remaining five species of the genus was also confirmed, illustrating the general application of markers isolated from the domestic horse to the evaluation of polymorphism in the other six species of the genus.     

Isolation of subunits from trypsin-cleaved sarcoplasmic reticulum Ca2+ transport adenosine triphosphatase.

Controlled tryptic digestion of purified rat skeletal muscle sarcoplasmic reticulum (Ca2+ + Mg2+)-adenosine triphosphate yields two products designated Fragments 3a and 3b with molecular weights of 65,000 and 56,000 respectively. The isolation of these products in high yield should facilitate exploration of the molecular characteristics of this adenosine triphosphatase. A simple, rapid method for accomplishing this isolation was developed which provides a high yield and utilizes mild conditions. The fragments obtained by this method were used to determine the phospholipid and sulfhydryl contents of Fragments 3a and 3b. In addition, information was obtained on the orientation of these adenosine triphosphatase components in the enzyme lipoprotein complex.