Nutritional and biochemical characterization of Methanospirillum hungatii.

To ascertain its physiological similarity to other methanogenic bacteria, Methanospirillum hungatii, the type species of the genus, was characterized nutritionally and biochemically. Good growth occurred in a medium consisting of mineral salts, cysteine sulfide reducing buffer, and an H2-CO2 (80:20) atmosphere. Addition of amino acids and B vitamins stimulated growth. Cell-free extracts contained methylcobalamin-coenzyme M methyltransferase, methylreductase, and formate hydrogenlyase. Cells contained coenzyme M and coenzyme F420. Coenzyme F420 was required for formate hydrogenlyase activity. Coenzyme F420 purified from M. hungatii had identical properties to that purified from species of Methanobacterium. The physiological basis of the family Methanobacteriaceae is strengthened by these findings.     

Aging effects on the elastin composition in the extracellular matrix of cultured rat aortic smooth muscle cells

Summary Elastin accumulation in the extracellular matrix of cultured rat aortic smooth muscle cells was monitored as a function of age. The effect of the animal donor age and time in culture in single or consecutive passages on the cells’ ability to accumulate total protein as well as elastin was evaluated. Smooth muscle cells were obtained from animals ranging in age from 2 d to 36 mo. Protein accumulation by the cells based on DNA content was similar regardless of which of the above aging parameters was examined. Although there were significant amounts of elastin present in the extracellular matrix of those cells originating from the younger animals (2 d and 6 wk old), little or none was detected in cell cultures derived from the oldest animals. A soluble elastin-like fraction which was isolated from the cultures of the 2-d-old rats seemed to be lacking in the cultures of cells from the 36-mo-old animals. This observation may, in part, explain the absence of insoluble elastin in the matrix of some cultures obtained from older animals. The data strongly suggest that the age of the donor animal from which the cells originate has the greatest influence on in vitro elastin accumulation. This study was supported by National Institutes of Health Grants HL 19717 and HL 13262.     

Phosphoglucomutase isozymes of red cells in Mus musculus: Additional polymorphism at PGM-1 compared by two electrophoretic systems

Phosphoglucomutase (PGM) of red cells was examined in 15 inbred strains of mice, using two different starch gel electrophoretic buffer systems. Two new alleles, Pgm-1 ^c and Pgm-1 ^d, were discovered at the Pgm-1 locus. Pgm-1 ^c was first identified in strain C3H/HeNWe and Pgm-1 ^d in 129/ReWl. No variation was observed at the Pgm-2 locus.Supported in part by USPHS Pre-doctoral Fellowship No. 5 F1 GM-32,680, USPHS Research Resources Grant No. 5-PO6 RR 00343-05, USPHS (National Cancer Institute) Chemotherapy Contract 71-2010, and Biomedical Sciences Support Grant FR 07037 to the University of Kansas.