The wall-bound invertase of morning-glory callus was solubilized by a systematic treatment with several chemicals. The degree of solubilization of wall-bound invertase was drastically altered by varying the pH values and chemical composition of the buffers. Triton X-100 and sucrose did not release invertase from cell walls. Comparative studies were made of some properties of wall-bound and solubilized invertases. These results suggest that the linkage of the enzyme to the cell wall is ionic. The cytoplasmic acid invertase, like the enzyme solubilized from cell walls, was adsorbed on cell walls, but the cytoplasmic neutral invertase was not. Based on these results, the linkage of acid invertase to cell walls, and a possible interrelationship and physiological role of both acid invertases and neutral invertase were discussed.

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Ramachandran (φ, ψ) maps have previously been used to depict regular, accessible conformations for amylose and other polysaccharides. Because monomeric bond lengths and valence angles are known to be fixed within narrow limits, generation of helical conformations by rotations (φ, ψ) of successive rigid monomers about the two bonds to the linkage oxygen atom was considered to be sufficient. By the Ramachandran method, given values of φ and ψ, combined with a set of residue atomic coordinates and fixed glycosidic angle, result in a helix that can be described in terms of n (number of residues per turn) and h (rise per residue). As we have previously discussed, however, large torsion angle differences within the ring exist for residues from different sources. These differences give rise to differing helical parameters for given values of φ and ψ The Ramachandran map is thus unable to provide a comprehensive picture of the allowed helical conformations. To remedy this difficulty, we have systematically examined combinations of varying values of n and h for feasibility. At each n-h grid point, virtual bond models were examined for reasonable stereochemistry by hard-sphere criteria. If any of the interatomic distances were less than the fully allowed values but greater than the minimally allowed figure, a given model was considered feasible as long as no more than five such marginal contacts occurred per glucose unit. Other than a 2.56 Å minimum figure for interoxygen distances, no special allowance was made for hydrogen bonding. The other, slightly smaller, minimally allowed values in the present work were considered reasonable because no attempt was made to optimize the model in order to relieve such short contacts. By examining 13 known residue geometries (all still in the ⁴C₁ conformation but with O(4)-O(1) length from 4.01 to 4.61 Å) and allowing models with glucosidic angles between 113°and 122°, a much wider range of helical shapes is found to be feasible than was previously reported. Values of n range from 2 to 10 and h ranges from 0.8 to 4.4 Å. The left-handed domain of the n-h map (negative values of n) includes all known amylose conformations, whereas several known extended shapes are not found within the right-handed domain. In both right- and left-handed domains, there is a large central region in which there are no known crystalline forms. Although these forms are likely to be important in amylose solutions, they are less likely to crystallize because of inefficient packing. These helices with moderate h cannot form inter-turn hydrogen bonds nor can they form double helices or “nested” single helices.

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The present tests had studied to find out the variations in diameter of starch granule and inorganic constituents among various potato varieties, and effects of fertilizer levels on these characteristics. Further, the relationships between these starch characteristics and agronomic characteristics were discussed. The each characteristics varied to the extent ranging 16.5-27.3 pm in diameter of starch granule, 141-374 mg in ash, 28-90 mg in P, 19-58 mg in K, 6-16 mg in Mg, and 0.9-3.6 mg/100 g in Ca. And these characteristics had highly significant correlations with agronomic characteristics. According to the increase in the amount of fertilizers, ash, P, K and Mg contents tended to decrease, while, Ca content showed a tendency to increase . As the results of the interaction between fertilizer and varieties, significant differences were observed in P, Mg and Ca contents.

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Chlorella vulgaris Al-ly-3 (11) was grown heterotrophically at 20°C, 30°C and 40°C. Intracellular and extracellular starches were isolated from the cells and culture broths by treatment with sonic oscillation and toluene. As the elevation of cultural temperature, some properties of respective starches were changed, while the others were not: (1) The amylose content was slightly decreased. (2) The content of total phosphorus was clearly decreased. (3)The maximum swelling power was considerably decreased and the gelatinization temperature was increased only in intracellular starches. (4) The crystalline type was independent on cultural temperatures. (5) The shape and size of starch granules did not change in all specimens. (6) No significant difference was found between intracellular and extracellular starches isolated from the same culture, in their contents of amylose and of total phosphorus, X-ray diffraction patterns, and absorption maxima of the iodine complexes.

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Characteristics of Okinawan wet-taro root starch, such as the shape of starch granules, amylose content, gelatinization temperature and paste viscosity, were investigated. The starch granules were revealed by the scanning electron microscopic observations to be small polygonal shape and their average diameter were 3 to 4 microns. Amylose was separated by two different extraction methods, namely, warm water extraction method and the Schoch's BuOH method and it was found that the glucose chain length of amylose obtained by the latter method was longer than this obtained by the former method. Amylose content was calculated to be 7 to 10% following the McCready's method and from this result this root starch could be classified into the low amylose starch group. From the photopastegrams of this starch, it became clear that this starch started its gelatinization at 72°C and thereafter the starch granules swelled rapidly. As to the Brabender's amylogram, the gelatinization temperature of 6% starch suspension was 78°C and the viscosity reached its highest value (570 B.U.) immediately after the start of gelatinization and the breakdown was about. 130 B.U.

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(1) Acid invertase was detected in cell walls of persimmon and soy bean callus. (2) The cell wall-bound invertases were solubilized by treatment with several chemicals. The degree of solubilization was drastically influenced by pH values and kind of buffer. About 70% of cell wall-bound invertase activity from both sources was solubilized with various kinds of 1 M salt solutions. However, about 15-20 % of invertase activity remained in the cell walls even after repeated solubilization with 1 M NaCI. Triton X-100 and sucrose did not release invertases from cell walls of both callus cells. (3) Invertase solubilized from persimmon callus cells was adsorbed on cell walls of persimmon and morning-glory callus cells. The enzyme released from morning-glory callus cells was adsorbed on cell walls of persimmon callus cells. (4) Properties of both cell wall-bound invertases were investigated. The optimum pH values of the persimmon and soy bean enzymes were 4.0 and 4.5, respectively. The soy bean enzyme was stable at pH values above 4. The persimmon enzyme was stable between pH 4 and 7.5. The optimum temperature for both enzymes was about 45°C. Both enzymes were stable at a temperature lower than 35°C, but above 35°C they rapidly lost their activity. Both enzymes hydrolyzed sucrose five times as fast as raffinose. Km values of the persimmon and soy bean enzymes for sucrose were 1.4 and 0.9 mM, respectively.

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