Last modified 21st Jul '95 © Birkbeck College 1995
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Protein Interactions
21st Jul, 13th Jul, 30th Jun, 26th Jun, 9th Jun, 6th Jun, 25th May ; see below
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To best appreciate the content of this chapter you need to INTERACTIVELY EXAMINE
a number of protein structures.
If you haven't done so already, we STRONGLY URGE you to install
the FREE molecular viewer software, RasMol and configure it to be automatically
invoked by chemical/MIME. See our Technology Page to find
out how.
This chapter aims to describe a few of the ways that proteins interact with each
other and with other large molecules in cells.
Protein-Protein Interactions
Proteins are directed to the
correct compartments of cells by binding to other proteins. Protein messengers
bind to protein receptors on the outer surface of cell membranes to send signals
between cells. Proteins form structural connections between cells. Some
inhibitors of enzymes are proteins. Proteins are modified and degraded by
enzymes. Interactions between different protein subunits are the
basis of allosteric changes in multimers. Protein-protein interactions underlie
very large-scale movements in organisms, such as muscle contraction.
Protein-Nucleic Acid Interactions
Certain proteins (histones) are an integral part of chromatin, which is the
wound form of DNA which constitutes chromosomes. Enzymes perform the
transcription of DNA to form RNA, while other proteins bind to specific regions
of DNA to promote or inhibit its transcription; thus gene regulation. In fact we mean just
about all the cellular machinery for synthesis, replication,
manipulation, modification, and degradation.
Protein Interactions with other biological (macro)molecules
This chapter also includes material on the enzymes which degrade polysaccharides
and lipids.
Some of the following sections are
still unfinished; some sections have been completed in the last week or
so. Meanwhile, theres still plenty there
to be getting on with...
: Inhibition page now ready
: Muscle Fibres page now ready
: Regulation page now includes link to Homeodomains section
: Regulation page now includes link to lac repressor section
: Proteases (Lysis- polypeptides) page now includes link to Serine Proteases section
: Muscle Fibres page 3 now includes link to
animation
: Protein hydration:
experimental and simulated
- Binding
- Lysis
- Conformational changes
Protein Degradation
- The turnover of protein is more than simply their proteolysis. Refer back to the
section covering this aspect in the Protein Synthesis chapter.
Protein-Solvent Interactions
If you have MAGE installed and configured for Chemical MIME, you can view the
Branden and Tooze,
Protein Science and
Protein Tourist Kinemages, some of which are relevant to this materi
al.
Again, refer to the
Technology Page if necessary.
There are some links to appropriate Kinemages within this chapter.
Credits
We wish to thank the following for material incorporated into this chapter
- Daniel Barsky
- Henry Brzeski
- Sophie Clarke
- Mark Dalton
- Mark Gerstein
- Donovan Haines
- Judith Murray-Rust
- Manuel Peitsch & Swiss-3DProt
- M.I.T.
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J. Walshaw &
Alan Mills