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Abstract— Frozen and unfrozen bovine brains were used to determine the extent of in situ degradation of myelin basic protein. The following three parameters were investigated. (1) The time interval between death and sampling of the tissue, (2) the effective temperature of the tissue during this interval, and (3) the effect of freezing and thawing on the subsequent autolysis of myelin basic protein. Polyacrylamide gel electrophoresis was carried out on unfrozen white matter solubilized with phenol‐formic acid–water. The resulting electrophoretic pattern showed no qualitative changes in the myelin basic protein after tissue incubation at 4° or 23°C for up to 24 h. When myelin basic protein was extracted, purified and quantitated, there was no apparent decrease within 24 h of incubation at 23°C. However, if the tissue was frozen and thawed prior to incubation, there was a rapid disappearance of myelin basic protein such that only 10% remained after 24 h of incubation. Basic protein extracted from frozen or unfrozen tissue that had undergone autolysis for up to 24 h was found to be encephalitogenic in guinea pigs. Electron microscopy of frozen and thawed material showed separation and fraying of myelin lamellae. It is postulated that the above morphological changes probably render the basic protein readily accessible to proteolytic enzymes.

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SWINE EXPOSURE TO |iC]DICHLORVOSincreased at a faster rate when fruits approached the ripe stage. All varieties attained almost the same percentage, about 90% of dry matter when ripe.The protein content at the green stage as shown in Table I is the highest and it is twofold higher than the concentration of the ripe stage (dry weight basis). There is no significant difference in the protein content of the three varieties studied with the same stage.Amino acid compositions of the three varieties are given in Table II. In all varieties there are identical patterns of amino acid composition and 17 amino acids were detected. The protein-rich green stage contained the highest concentration of amino acids with more glutamic acid, aspartic acid, lysine, leucine, alanine, and serine than the other two stages of maturity. The data in Table II show that total and free amino acids concentrations are considerably different in the three varieties for the three stages of maturity. This seems to be associated with the protein contents of the three stages of development (Table I). The data also show for the three varieties at the yellow and completely ripened stages that glutamic acid, aspartic acid, lysine, leucine, proline, and glycine were present at high concentrations.

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