Assay of reducing end-groups in oligosaccharide homologues with 2,2'-bicinchoninate.

For the first time, reducing values of homologous series of oligosaccharides have been determined by the 2,2'-bicinchoninate assay. The extent of Cu2+ reduction was monitored by spectrophotometric measurement of Cu+/2,2'-bicinchoninate complexes. Conditions of the assay were optimized so that relatively uniform reducing values were obtained with oligosaccharides derived from starch, polygalacturonic acid, and chitin, regardless of degree of polymerization. The uniform values resulted because members of each oligosaccharide series were oxidized to similar levels beyond the aldonic acid stage, while oxidation was limited to the reducing-terminal residue. This conclusion was based on direct measurements of quantitative loss of paramagnetic copper (Cu2+) by electron paramagnetic resonance spectroscopy.     

N-acetylmuramoyl-L-alanine amidase assay based on specific radioactive labeling of muropeptide L-alanine: quantitation of the enzyme activity in the autolysin deficient Bacillus subtilis 168, flaD strain.

A sensitive and highly reproducible assay for N-acetylmuramoyl-L-alanine amidase (EC 3.5.1.28) was devised, based on specific and homogeneous L-[14C]alanine labeling of the substrate, the peptidoglycan. The method involves partial purification of both the enzyme and the substrate and monitoring the muropeptide cleavage by coupling fluorodinitrobenzene to freed L-alanine NH2 groups. After acid hydrolysis of the substrate, the resulting DNP-L-alanine and L-alanine are separated by TLC, and radioactive counts in relevant spots are determined. Application of the method to the autolysin-endowed strain and an autolysis-deficient flaD-bearing mutant has revealed (i) that the N-acetylmuramoyl-L-alanine amidase behaves like an endoenzyme with an apparent Kcat(s-1) of 40, and (ii) that the residual enzyme activity in the flaD bearing strain amounts to 2.5 (+/- 0.1)% of that of the parent strain.     

Quantitative determination of albumin in urine by on-line immunoadsorptive cleanup and reversed-phase chromatography

Albumin in urine is selectively adsorbed on an immunoadsorber (human serum albumin-specific antibodies coupled covalently with a silica stationary phase) and after elution with 0.1% HCl is quantitatively determined by reversed-phase chromatography with detection of native fluorescence. The optimization of sample preparation and characteristics of the method such as recovery, linearity, reproducibility, detection limit, and selectivity are discussed.     

PHYTOCHROME CONTROL OF ROOT GROWTH RATE IN LEMNA SPECIES

Root growth rate was studied in Lemna gibba L. (strains Gl and G3) and L. minor L. in relation to low energy red and far-red light treatments. Far-red treatments inhibited growth rate; inhibition was abolished upon subsequent treatment with red light. These effects can be observed after an 18-hr growth period. This red/far-red photoreversible response suggests that root growth in L. gibba L. and L. minor L. is under phytochrome control.     

Family resemblance for anthropometric and blood pressure measurements in Black Caribs and Creoles from St. Vincent Island

This paper examines family resemblance for five anthropometric measurements (height, weight, triceps skinfold, upper arm circumference relaxed [UACR] and flexed [UACF] and for systolic and diastolic blood pressure in a group of adult Caribbean islanders of primarily African ancestry. Six hypotheses about family resemblance are tested by using path analysis and likelihood ratios. Significant intergenerational transmission is found only for height and UACR. For weight, UACF, and diastolic blood pressure, non-transmissible sibling resemblance is the primary component of family resemblance, although significant marital resemblance exists for diastolic blood pressure. Triceps skinfold and systolic blood pressure show no evidence of any family resemblance. Although results for highly heritable traits such as height are comparable to reports from other populations, measurements with a large contribution from common family environment or residual environmental effects, such as triceps skinfold or blood pressure, have much lower family resemblance in this population than in other populations. We hypothesize that this difference is due to the fact that adult children and their parents do not share a common household in this culture and to the presence of major nonfamilial environmental factors contributing to obesity and hypertension in this population.     

Zwei neue Formen vonPotentilla

Ohne Zusammenfassung