Biomedical subjects

N Balaban

Publications and source records attributed to N Balaban.

22 records · Page 2Linked to original sources

PubMed1990

The association of glycosomal enzymes and microtubules: a physiological phenomenon or an experimental artifact?

Subpellicular microtubules isolated from Trypanosoma brucei parasites were fractionated on a phosphocellulose column, and the trypanosomal p52 microtubule-associated protein was eluted along with two other proteins of 41 and 36 kDa. These proteins were found to be the glycosomal enzymes aldolase (41 kDa) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH, 36 kDa) by enzyme activity, antibody cross-reaction, and N-terminal sequencing. These enzymes were coprecipitated with tubulin in the presence of taxol, and aldolase had the capacity to polymerize tubulin and crosslink microtubules. Immunolocalization of anti-aldolase and anti-GAPDH antibodies did not show an interaction between these enzymes and the subpellicular microtubules. The question whether the copurification of aldolase and the subpellicular microtubules could reflect a physiological phenomenon or may be an experimental artifact is discussed.

Alkaloids↗

PubMed1989

Isolation of a subpellicular microtubule protein from Trypanosoma brucei that mediates crosslinking of microtubules.

The cell body of Trypanosomatidae is enclosed in densely packed, crosslinked, subpellicular microtubules closely underlying the plasma membrane. We isolated the subpellicular microtubules from bloodstream Trypanosoma brucei parasites by use of a zwitterion detergent. These cold stable structures were solubilized by a high ionic strength salt solution, and the soluble proteins that contained tubulin along with several other proteins were further fractionated by Mono S cation exchange column chromatography. Two distinct peaks were eluted containing one protein each, which had an apparent molecular weight of 52 kDa and 53 kDa. (Mr was determined by SDS-gel electrophoresis). Only the 52 kDa protein showed specific tubulin binding properties, which were demonstrated by exposure of nitrocellulose-bound trypanosome proteins to brain tubulin. When this protein was added to brain tubulin in the presence of taxol and GTP, microtubule bundles were formed with regular crosslinks between the parallel closely packed microtubules. The crosslinks were about 7.2 nm apart (center to center). Under the same conditions, but with the 53 kDA protein or without trypanosome derived proteins, brain tubulin polymerized to single microtubules. It is thus suggested that the unique structural organization of the subpellicular microtubules is dictated by specific parasite proteins and is not an inherent property of the polymerizing tubulin. The in vitro reconstituted microtubule bundles are strikingly similar to the subpellicular microtubule network of the parasite.

Animals↗

PubMed1989

[Bacteriological comparison of colostrum and mature human milk].

15 colostrum and 15 mature milk were examined in bacteriology laboratory in Ankara Numune Hospital. The number of colonies cultured at "0" hour, 6-24 after at room temperature 24 after refrigeration were evaluated. It was noticed that the cultures obtained at 0 and 6 hours and after refrigeration did not reveal much bacteria. But cultures obtained from Colostrum and mature milk after 24 hours at room temperature revealed colonies. The colonisation in mature milk was significantly higher than the colostrum.

Adolescent↗

PubMedDate not supplied

Antioxidant activity of seminal plasma in fertile and infertile men.

This study was conducted to evaluate and compare the total antioxidant capacity among fertile and infertile men. Thirty infertile patients and 20 fertility-proven healthy donors with normal sperm analysis were included in the study. Total antioxidant capacity, zinc and fructose levels of seminal plasma, and various sperm parameters were compared among fertile controls and idiopathic infertility patients prospectively. The mean antioxidant capacity of fertile controls (2.02 +/- 0.16 mmol/L) was significantly higher than that of the infertile patients group (1.78 +/- 0.23 mmol/L) (p < .01). Furthermore, asthenozoospermic and asthenoteratozoospermic groups had significantly lower mean antioxidant values (1.73 +/- 0.11 and 1.64 +/- 0.13, respectively) when compared to fertile control group (p < .01). The mean fructose level was significantly lower in the fertile control group and mean zinc level was significantly lower in the entire infertile group. On the other hand, antioxidant capacity is positively correlated to sperm motility (p = .001). Decreased antioxidant capacity was associated with impaired sperm function as a result of either increased ROS production or insufficient antioxidant capacity.

Antioxidants↗