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W D Huse

Publications and source records attributed to W D Huse.

23 records · Page 2Linked to original sources

Cloning of the immunological repertoire in Escherichia coli for generation of monoclonal catalytic antibodies: construction of a heavy chain variable region-specific cDNA library.

Efficient generation of catalytic antibodies is uniquely dependent on the exact nature of the binding interactions in the antigen-antibody complex. Current methods for generation of monoclonal antibodies do not efficiently survey the immunological repertoire and, therefore, they limit the number of catalysts that can be obtained. We are exploring methods to clone and express the immunological repertoire in Escherichia coli. As the essential first step, we present here a method for the establishment of a highly diverse heavy chain variable region library. Consequently, it should now be possible to express and recombine the heavy and light chain variable region fragments to generate a large array of functional combining portions of the antibody molecule. This technology may provide an alternative to the hybridoma methodology for accessing the monoclonal antibody specificity of the immune system.

Animals↗

Lambda ZAP: a bacteriophage lambda expression vector with in vivo excision properties.

A lambda insertion type cDNA cloning vector, Lambda ZAP, has been constructed. In E. coli a phagemid, pBluescript SK(-), contained within the vector, can be excised by f1 or M13 helper phage. The excision process eliminates the need to subclone DNA inserts from the lambda phage into a plasmid by restriction digestion and ligation. This is possible because Lambda ZAP incorporates the signals for both initiation and termination of DNA synthesis from the f1 bacteriophage origin of replication (1). Six of 21 restriction sites in the excised pBluescript SK polylinker, contained within the NH2-portion of the lacZ gene, are unique in lambda ZAP. Coding sequences inserted into these restriction sites, in the appropriate reading frame, can be expressed from the lacZ promoter as fusion proteins. The features of this vector significantly increase the rate at which clones can be isolated and analyzed. The lambda ZAP vector was tested by the preparation of a chicken liver cDNA library and the isolation of actin clones by screening with oligonucleotide probes. Putative actin clones were excised from the lambda vector and identified by DNA sequencing. The ability of lambda ZAP to serve as a vector for the construction of cDNA expression libraries was determined by detecting fusion proteins from clones containing glucocerbrosidase cDNA's using rabbit IgG anti-glucocerbrosidase antibodies.

Actins↗

Time course of miniature postsynaptic potentials at the Mauthner fiber giant synapse of the hatchetfish.

The hatchetfish Mauthner fiber is presynaptic to 8-14 large myelinated axons in the medulla; the large ('giant') synapses formed by these fibers appear to be nicotinic cholinergic. Miniature postsynaptic potentials (mPSPs) were recorded from single identified synapses. The mPSPs were averaged to more accurately determine their shape; the rise time was approximately 70 microseconds, and the fall usually was biphasic with time constants of decay for the two phases of 280 and 800 microseconds. In 25% of the records analyzed a third, slow tail of decay was seen which had an average decay constant of 4.2 ms. The biphasic decay of mPSPs largely accounts for the similar shape of the postsynaptic current following a presynaptic impulse, which is described in the accompanying paper.

Animals↗

Postsynaptic currents at the Mauthner fiber giant synapse of the hatchetfish.

Postsynaptic currents (PSCs) at the giant synapse between Mauthner and giant fibers of the hatchetfish Gasteropelecus were studied under voltage clamp. This axo-axonic synapse lies in the central nervous system beneath the floor of the 4th ventricle where electrodes can be closely positioned both pre- and postsynaptically. Transmission is nicotonic cholinergic. The PSCs produced by Mauthner fiber impulses rise rapidly to a peak and decay in two phases; an early more rapid phase is followed by a late slower phase. The slope conductance of the peak amplitude of the PSCs declines at more inside positive potentials. The late phase of decay is exponential and voltage dependent, becoming faster for PSCs evoked at more inside positive potentials. At potentials positive to about -40 mV the late phase merges with the early phase. The decay rate constant of the slowest phase is exponentially related to voltage for potentials negative to about -10 mV, but becomes less voltage dependent for more positive potentials. The peak current is independent of whether it is evoked during inward or outward active currents of the electrically excitable membrane, and two phase decays are observed in PSCs of reduced quantal content. Thus, changes in slope conductance and two phase decays are not due to series resistance or interactions between quanta. PSCs can be modeled by a 3 state reaction scheme in which closed channels open when they bind transmitter and then can pass to a second closed state with receptor still bound such that they must return through the open state before losing their transmitter and returning to the resting, closed state.

Animals↗