From owner-metabolic-reg@net.bio.net Sun Oct 15 23:00:00 1995 Path: biosci!bcm.tmc.edu!cs.utexas.edu!news.sprintlink.net!simtel!harbinger.cc.monash.edu.au!newshost.anu.edu.au!NewsWatcher!user From: cam@rschp1.anu.edu.au (Cameron Neylon) Newsgroups: bionet.metabolic-reg Subject: Some idle speculation Date: Mon, 16 Oct 1995 15:39:58 +1000 Organization: ANU Lines: 27 Message-ID: NNTP-Posting-Host: 150.203.96.61 Always worth trying to start an arguement I guess; A couple of thoughts; The water content of mitchondria is very low, less than that of a protein crystal apparently, on the order of 20% (or have I got the number wrong) Anyway assuming that the water content of the cytosol is similarly very low, that would seem to imply that serious protein protein interactions would be required just to keep metabolites in moving through the various pathways. That in fact metabolites would _have_ to be shuttled directly from enzyme to enzyme or run the risk of getting stuck into the gel of the cytosol somewhere. But at the recent FAOBMB conference in Sydney, one paper presented evidence that the 'tumbling rates' of two glycolytic enzymes are close to that of the enzymes in free solution. There was an exception to this (I think it was pyruvate kinase) [I can dig up the reference if people like, I just don't have it to hand] Anyway, just lead me to wondering which way things were leaning in the metabolite shuttling debate. Certainly a subject worth debating, and this seems a god place to do it. -- Cameron Neylon +61 6 251 1118 (Home) Research School of Chemistry +61 6 249 4181 (Lab) Australian National University or more likely cam@rsc.anu.edu.au .