Biotechnology Commons^™

Reduction Of Ferric Leghemoglobin In Soybean Root Nodules, Keuk-Ki Lee, Robert V. Klucas

Department of Biochemistry: Faculty Publications

Reduction of ferric leghemoglobin to ferrous leghemoglobin in soybean nodules (Glycine max [L.] Meff. cv Woodworth) was studied using a spectrophotometer equipped with an in-cell space diffuse reflectance accessory. Nodule slices prepared and scanned under nitrogen gas showed a ferrous leghemoglobin absorption spectrum. Nodule slices equilibrated with 100% O₂ or air exhibited two absorption bands characteristic of oxygenated leghemoglobin. The addition of CO shifted those bands to CO leghemoglobin absorption bands. Potassium ferricyanide was not effective in oxidizing ferrous to feffic leghemoglobin in nodule slices. However, ferric leghemoglobin was formed by treating the nodule slices with hydroxylamine, and …

Reversible Dark-Induced Senescence Of Soybean Root Nodules, N. E. Pfeiffer, Nasir S.A. Malik, Fred W. Wagner

Department of Biochemistry: Faculty Publications

Nodule senescence was induced in intact soybean Glycine max. (L.) Merr., cv Woodworth plants by an 8-day dark treatment. Dark-induced senescence resulted in the complete loss of acetylene reduction activity, a 67% loss of total soluble protein, and an almost complete loss in total leghemoglobin of nodule extracts. Isoelectric focusing gels demonstrated a preferential loss of certain proteins, which was correlated with an increase in endoprotease specific activity toward azocasein. Nodules were completely green after the 8-day dark treatment. If plants were returned to a normal photoperiod after 8 days in the dark, nodules recovered from the dark treatment in …

Proteolytic Activity In Soybean Root Nodules: Activity In Host Cell Cytosol And Bacteroids Throughout Physiological Development And Senescence, Nancy E. Pfeiffer, Cecilia M. Torres, Fred W. Wagner

Department of Biochemistry: Faculty Publications

Root nodules were harvested from chamber-grown soybean (Glycine max L. Merril cv Woodworth) plants throughout development. Apparent nitrogenase activity (acetylene reduction) peaked before seeds began to develop, but a significant amount of activity remained as the seeds matured. Nodule senescence was defined as the period in which residual nitrogenase activity was lost. During this time, soluble protein and leghemoglobin levels in the host cell cytosol decreased, and proteolytic activity against azocasein increased. Degradative changes were not detected in bacteroids during nodule senescence. Total soluble bacteroid protein per gram of nodule remained constant, and an increase in proteolytic activity in …

Peptidohydrolases Of Soybean Root Nodules, Nasir S. A. Malik, N. E. Pfeiffer, D. R. Williams, Fred W. Wagner

Department of Biochemistry: Faculty Publications

Nodule extracts prepared from Glycine max var Woodworth possessed endopeptidase, aminoptidase, and carboxypeptidase actiities. Three distinct endopeptidase activities could be resolved by disc-gel electrophoresis at pH 8.8. According to their order of increasing electrophoretic mobility, the first of these enzymes hydrolyzed azocasein and n-benzoyl-LLeu-β-naphthylamide, while the second hydrolyzed n-benzoyl-L-Arg-/8- naphthylamine (Bz-L-Arg-/βNA), n-benzoyl-L-Arg-β-nitroanilide (Bz-L-Arg-βNA), and azocasein. The third endopeptidase hydrolyzed Bz-L-Arg-βNA, Bz-L-Arg-βNA, and hemoglobin. Fractions of these enzymes extracted from electrophoresis gels were shown to have pH optima from 7.5 to 9.8. AU of the endopeptidases were completely inhibited by diisopropylphosphorofluoridate, demonstrating that they were serine proteases.

Recollections, George W. Beadle

Department of Biochemistry: Faculty Publications

In these exciting times when elementary and high schools teach modern biology, including many of the intricacies of biochemical genetics, the long slow process by which our present knowledge in this area was gained is not often fully appreciated. A third of a century elapsed before Mendel’s work was "rediscovered" and properly appreciated. Archibald E. Garrod’s (1) prophetic appreciation of the relation genetics and biochemistry, beginning soon after the so-called rediscovery of Mendel, lay fallow for more than forty years despite the fact that he published widely and relatively voluminously. As late as a quarter of a century after the …

Characterization Of A Fatty Acid Synthetase From Corynebacterium Diphtheriae, Herman W. Knoche, Kirston E. Koths

Department of Biochemistry: Faculty Publications

A fatty acid synthetase from Corynebacterium diphtheriae has been purified to a specific activity of 450 nmoles of malonyl coenzyme A incorporated per min per mg. The enzyme is optimally active in 0.5 M phosphate buffer. C. diphtheriae appears to be the most primitive organism having a multienzyme complex for fatty acid synthesis.

Palmityl Coenzyme A Inhibition Of Fatty Acid Synthesis, Herman Knoche, Theodore W. Esders, Kirston Koths, Konrad Bloch

Department of Biochemistry: Faculty Publications

The effects of acyl-CoA derivatives (C₈ to C₂₀) on the activity

of the fatty acid synthetases from yeast and Corynebacterium

diphtheriae have been examined. Both enzyme

systems are inhibited by the longer chain acyl thioesters

(C₁₆ to C₂₀) and protected against this inhibition by bovine

serum albumin (BSA). Identical relief from acyl-CoA inhibition

is provided by the 6-0-methylglucose-containing

lipopolysaccharide (MGLP), from Mycobacterium phlei. It

is shown that MGLP forms a stable complex with palmitylCoA.

This interaction accounts for the BSA-like effects of

the polysaccharide. BSA and MGLP have two further effects

on the fatty …

The Structure Of An Ornithine-Containing Lipid From Thiobacillus Thiooxidans, Herman W. Knoche, Jessup M. Shively

Department of Biochemistry: Faculty Publications

The structure of an ornithine-containing lipid from Thio-bacillus thiooxidans

has been elucidated. Methanolysis of

the lipid released methyl cis-ll,lZ-methylene-Z-hydroxyoctadecanoate.

Acid hydrolysis of the residue yielded ornithine

and a mixture of fatty acids, the major components of

which were 3-hydroxyhexadecanoic and 2-hexadecenoic

acids. Identification of the 3-hydroxy fatty acid was based

on the thin layer chromatographic mobilities of the acid, its

methyl ester, the methyl ether, and acetate derivatives of its

methyl ester, on the equivalent chain lengths of the derivatives

of the acid and the acid obtained by oxidation of the

natural acid with permanganate, and on mass spectral studies. …

The Identification Of Cis-Ii, I2-Methylene-2-Hydroxyoctadecanoic Acid From Thiobacillus Thiooxidans, H. W. Knoche, J. M. Shively

Department of Biochemistry: Faculty Publications

A polar fatty acid has been observed as a component of an

ornithine-containing lipid of Thiobacillus thiooxidans. A

comparison of thin layer chromatographic mobilities of reference

compounds to those of the natural acid and its derivatives

suggested that the acid was a 2-hydroxy fatty acid.

The presence of a cyclopropane function in the acid was

indicated by l4e-Iabeling experiments and infrared spectroscopy.

Mass spectrometry of the methyl ester and the acetylated

methyl ester of the natural acid provided a molecular

weight for the acid. Equivalent chain lengths were determined

for the natural acid, the acid obtained by oxidative

decarboxylation of …

Carbohydrate And Lipid Metabolism During Germination Of Uredospores Of Puccinia Graminis Tritici, J. M. Daly, H. W. Knoche, M. V. Wiese

Department of Biochemistry: Faculty Publications

Uredospores of Puccinia gramintis (Pers.) tritici (Eriks. and Henn.) were uniformly labeled with ¹⁴C by permitting the host (Triticuml aestivum L.) to carry out photosynthesis in ¹⁴CO₂ during the process of spore production by the obligate parasite. The use of ¹⁴C labeled spores provided advantages in a study of the utilization of endogenous substrates at frequent intervals with small amounts of spores under conditions conducive to germination.

Concerning The Site Of Nitrogen Absorption In Rats Fed Autoclaved Or Raw Soybean Oil Mea, Raymond Borchers

Department of Biochemistry: Faculty Publications

Carroll, Hensley, and Graham (1) have concluded that much of the nitrogen absorption in rats fed raw soybean oil meal must take place in the cecum. This conclusion was reached from data showing that the apparent digestibility of raw soybean nitrogen in the terminal 20% of the small intestine was 32.65%, whereas in the feces the value was 76.96%. Values reported, for apparent digestibility of heated soybean nitrogen were 78.66% and 81.78%, respectively. This observation presented a notable advance in explaining the lower nutritive value of raw soybeans compared with autoclaved soybeans. It therefore seemed advisable to repeat this work …

Riboflavin Production By Molds, George L. Peltier, Raymond Borchers

Department of Biochemistry: Faculty Publications

Very little information is at hand regarding the ability of molds to synthesize riboflavin. Few citations pertaining directly to riboflavin production by true

molds are available. Pontovich (1943) found as much as 2 mg riboflavin per g

of Aspergillus flavus mycelium. Tanner et at. (1945) determined the quantity of

riboflavin in the submerged fermentation media of Penicillium chrysogenum.

The highest value found was 1. 36 mg per ml. The primary purpose of this study

was to screen several hundred isolates, recently obtained from soil, crop residues,

and composts, for their ability to produce riboflavin on a wheat bran substrate.

Threonine Deficiency In Hydrolysates Of Zein Prepared By Autoclaving, Raymond Borchers, John R. Totter, Clarence P. Berg

Department of Biochemistry: Faculty Publications

In a previous paper (Borchers and Berg, 1942) we showed that

autoclaving zein with sulfuric acid longer than necessary for complete

hydrolysis causes destruction and racemization; either of

these might account for the failure of such a hydrolysate to

promote growth in young rats when substituted for a hvdrolysate,

prepared by refiuxing, in a diet which produced moderate growth.

It seemed to us that this deterioration in the dietary protein might

well be the result primarily of essential amino acid deficiencies

which could be detected and overcome by appropriate supplementation.

Because threonine is known to be present in zein in …

Tryptophane Metabolism X. The Effect Of Feeding 1(-)-, Dl-, And D(+)-Tryptophane, D(-)And Dl-(Β-3-Indolelactic Acid,(Β-3-Indolepyruvic Acid, And L(-)Kynurenine Upon The Storage Of Liver Glycogen And The Urinary Output Of Kynurenic Acid, Kynurenine, And Total Acetone Bodies, Raymond Borchers, Clarence P. Berg, Newton E. Whitman

Department of Biochemistry: Faculty Publications

The amount of tryptophane required for maintenance and growth is small (2). When an excess is supplied to some animals, kynurenic acid is excreted (3) and, under certain conditions, kynurenine also (4). Although these are quantitatively the most important of the known metabolic products of tryptophane, the amounts excreted in extensive tests in the dog and rabbit have usually accounted for less than half, more often for less than a third, of the tryptophane administered (4-6).

The Effect Of Conditions Of Hydrolysis And Of Prolonged Heating Upon The Optical Rotation Of Sulfuric Acid Hydrolysates Of Zein, Raymond Borchers, Clarence P. Berg

Department of Biochemistry: Faculty Publications

Some time ago we observed that a sulfuric acid hydrolysate of zein prepared in an autoclave at 165˚ did not support growth in young rats when it was supplemented with certain amino acids, even though the same amino acids, added to a hydrolysate prepared by refluxing, permitted moderate growth. Since the optical rotation of the autoclaved hydrolysate was lower than that of the refluxed, either destruction or racemization of essential constituents, or both, might have occurred. Loss of amino nitrogen and production of extra ammonia upon prolonged autoclaving of proteins with acids have been noted by Van Slyke (1912) …