RATE OF RESPIRATION AS RELATED TO AGE

In the present paper it is shown that as the leaves of corn, sorghum, wheat, and oats increase in age there is a decrease in rate of respiration; but that as the leaves become still older (past about middle age) the rate gradually increases.     

Antibodies that recognize phosphodiester-linked amino-N-acetylglucosamine-1-phosphate residues

An affinity chromatography procedure was developed for isolating antibodies that recognized phosphodiester-linked alpha-N-acetylglucosamine-1-phosphate (alpha-GlcNAc-1-P) residues. The affinity resin consisted of uridine-5'-diphospho-alpha-N-acetylglucosamine (UDPGlcNAc) conjugated to Sepharose. Antiserum prepared against Proteinase 1 from the cellular slime mold, Dictyostelium discoideum was used as a source of the anti-alpha-GlcNAc-1-P antibodies. Immunoblot assays showed that the affinity-isolated antibodies recognized phosphoglycosylated subunits of Proteinase 1, and that UDPGlcNAc blocked this interaction.     

Evidence for phosphoryl moieties in a proteinase from Dictyostelium discoideum.

A proteinase (called Proteinase I) present in myxamoebae of the cellular slime mold, $\text{Dictyostelium}\text{discoideum}$, was labeled $\text{in}\text{vivo}$ with [³²P] by growth of cells on media containing [³²P] orthophosphate. The labeled proteinase was purified to apparent homogeneity and characterized by dissociation chromatography and quantitative immune-precipitin analysis. Based upon the results of these studies it was concluded that phosphoryl moieties were tightly associated (presumably covalently bonded) with the polypeptide subunits of Proteinase I.