A novel approach to isolation and functional characterization of genomic DNA from the methylotrophic yeast Hansenula polymorpha

A novel approach to isolation and functional characterization of the Hansenula polymorpha genes basing on the use of two strains of different origin is described. One of these strains is better suited for the isolation of genomic DNA fragments, while the other is preferable for their functional analysis. Thirty three genomic sequences governing expression of a reporter protein have been isolated. Analysis of the sequence encoding a homolog of the Saccharomyces cerevisiae cofilin revealed two introns. Another isolated DNA fragment encoded a homolog of the S. cerevisiae V ps10p. Disruption of the corresponding gene resulted in secretion of a vacuolar protein, carboxypeptidase Y, into the culture medium.     

Revisiting Paradoxical Situations Associated with Hydrocephalus

Biophysics - A case study of hydrocephalus shows the vagueness of the concept of the “norm” as used in medicine. Self-organizing dynamic stability in biosystems can go far beyond the...     

Clock synchronization in various modes of regulation

In this study, which is dedicated to the participants of I. M. Gelfand's scientific seminar, the regulation mechanisms for the clock synchronization in an isolated biological community are analyzed. A comparison has been carried out of the time consumed and the work done taking into account the specific error value for three modes of regulation: centralized regulation, centralized hierarchy regulation, and self-organization based on paired interaction. The results of the study may have different biophysical applications.     

Structural changes in proteins of the bacteriophage T4 basal plate resulting from the attachment of long fibrils

The effect of the attachment of long tail fibers on the structure of proteins of the bacteriophage T4 baseplate was studied by digital processing of electron microscopic images. The attachment of the long fibers was found to result in dramatical changes of the proteins of the baseplate plag, while the wedges, to which the long fibers are attached, undergo only slight changes. We studied the baseplates with one to six attached fibers and found that the attachment of one fiber resulted in the change of the entire baseplate, although the wedge located in the vicinity of the fiber attachment changed to a greater extent. Only after the attachment of three and more fibers the changes of the same kind occurred through the entire baseplate.     

Correlation between the level of fluorescent aging pigments in homogenates of the rat cerebral cortex and the constant brain potential during late ontogenesis

A strong correlation (R = 0.5 + 0.88) was found between the constant potential level of the rat brain and the content of aging pigments in the brain cortex homogenates. The latter was measured by synchronous scanning of luminescence in each hemisphere separately.     

Do external or internal reasons determine the synchronicity of cell division at early stages of embryogenesis?

By the method of computer simulation the 2-dimensional diagram, which reveals the dependence of the degree of cell division synchronization on genetic variation and environment variety, was obtained. The diagram demonstrates many trajectories of the cell system self-organization. It was shown that synchronization on the early stages of loach spawn embryogenesis may be obtained by the combination of various internal and external factors.     

Antibody engineering: Molecular constructor on the basis of barnase-barstar module

Today, antibody engineering for clinical applications is a rapidly progressing field of science and a big business. The basic functions of an antibody can be spatially differentiated and attributed to various structural domains of a molecule. Therefore, each of them may be an object for engineering with the aim of using a definite antibody function. In this sense, the potential of antibodies is unique. In this article, recent achievements and current problems of antibody engineering are briefly reviewed. The main attention is focused on a molecular constructor that allows for obtaining, with the help of a versatile barnase-barstar module, mono- and multivalent miniantibodies and their derivatives with outlined properties.