No abstract

No abstract

Isoelectric focusing of human parotid saliva reveals different alpha-amylase patterns reflecting qualitative and quantitative variations. A puzzling pattern, which shows three different amylase gene products, was found in four individuals. Based on this observation a model is presented in which the salivary amylase gene is duplicated. Family studies show that the AMY1*A2 gene forms a haplotype with the normal gene, AMY1*A1, whereas the AMY1*A3 gene still exists in a single form. The absence of homozygote 2-2 in offspring of 1-2 X 1-2 marriages and in population material, and the fact that the variant protein makes up about only 20-30% of the total amylase protein in heterozygotes can be considered as additional evidence supporting the hypothesis. The possibility that cis-acting regulatory variants are involved in the patterns with quantitative variation is discussed.

No abstract

en studied in yeast cell.~ that were: either fragmented by shaking intact cells with gta~,; heads ,~r by" [r~-potonic r,r isotonic disruption of protoplasts prepared fr,~m intact cPIIx. z. The non-sp~-ific acid pho~ph,tta_~t, with ontirrmm activity at pH between 3 and 4 wa.~ shown to ~mcur in the cell wall of commercial baker's yea_~t. As s,,;ne substrates of the enzyme can only enter that part of the cell vtflume corresponding to the cell wall and the act :vity is not increased by frt'Pzing and thawing the yeast, it was concluded that all the enzyme ix located here. 3. The highly specific a-glyccrophospi~tl~t-~, i~ entirely present in the unstractured c vtopla.sm of a i7-h culture of Saccharottu'ces carlxbergensis (No. 74}. 4. S. carlsbergensis ~No. 74) contains ~mlv one non-specific alkaline phospl~atasc. The distribution depends ut~m tl|t~ age of the culture: In ,t culture aged 17 h twothirds of the enzyme is bound to particles sedimenting from 3900 × g to roo ooo :~" g. and one-third is s~luble. In a culture ;tgttd 24 h 7o-85'.'.,~ of the enzyme is fouml in the soluble fraction, and only a small amount ix p,..ticle bound.