GPE and GPE analogues as promising neuroprotective agents.

The tripeptide glycine-proline-glutamate (GPE) is the naturally cleaved N-terminal tripeptide of insulin-like growth factor-1 (IGF-1) in brain tissues by an acid protease. Although GPE does not bind to IGF-1 receptors and its mode of action is not clear, in vitro studies have demonstrated its ability to stimulate acetylcholine and dopamine release, as well as to protect neurones from diverse induced brain injures. More importantly, GPE has been shown to have potent neuroprotective effects in numerous animal models of hypoxic-ischemic brain injury and neurodegenerative diseases such as Parkinson's, Alzheimer's and Huntington's diseases. As a consequence, GPE was suggested to be a potential target for the rational design of neuroprotective agents. Unfortunately, the use of GPE as a therapeutic agent is limited because of its unfavorable biochemical and pharmacokinetic properties. This review will focus on structural modifications performed on the GPE molecule in order to obtain bioactive analogues with increased pharmacokinetic profile useful for the treatment of central nervous system (CNS) injures and neurodegenerative disorders.

Cell-wall protein profiles of dairy thermophilic lactobacilli.

SDS-PAGE fingerprinting of cell-wall proteins extracted from 119 strains belonging to different species of lactic acid bacteria have been compared. The method of extraction and electrophoretic separation utilized in this work was found to be a reliable and rapid way for characterizing thermophilic lactobacilli species and strains. A protein of approximately 50 kDa was found to be characteristic for all the Lact. helveticus strains, and two cell-wall proteins of about 20 and 30 kDa were typical of the species Lact. delbrueckii, but the discrimination between the subspecies lactis and bulgaricus was not possible by the electrophoretic technique used. The other thermophilic species studied in this work presented cell-wall protein patterns that permitted their differentiation from both Lact. helveticus and Lact. delbrueckii.

Mucronate, Mc, a dominant gene of maize which interacts with opaque-2 to suppress zein synthesis.

This paper describes a new dominant mutation of maize, Mc, which interferes in the endosperm with the synthesis of storage proteins. The mutant is characterized by an opaque phenotype; it reduces the deposition of zein and it increases the level of methionine. The mutation is specifically related to storage protein synthesis since soluble and insoluble carbohydrates are present at normal levels. The main interest of this mutant lies in its synergistic interaction with opaque-2 in repressing zein synthesis. In the double mutant o2Mc the accumulation of zein is reduced to less than 10% of that of the normal endosperm. The control on zein synthesis exerted by the double mutant is at the level of production or stability of translatable zein mRNAs. The double mutant o2Mc germinates well offering the opportunity of using it in biochemical and molecular studies related to storage protein synthesis; the reduced endosperm weight of o2Mc negates its practical utilization in breeding maize for quality.