Path: utzoo!attcan!utgpu!watmath!iuvax!rutgers!sunybcs!boulder!pell
From: pell@boulder.Colorado.EDU (Anthony Pelletier)
Newsgroups: sci.bio
Subject: Re: Hybrid vigor
Keywords: ATP pool, "fast" and "slow" variants of an enzyme
Message-ID: <10691@boulder.Colorado.EDU>
Date: 11 Aug 89 15:42:10 GMT
References: <4869@drivax.UUCP> <3411@internal.Apple.COM> <5983@lynx.UUCP> <3452@internal.Apple.COM> <10659@boulder.Colorado.EDU> <24513@iuvax.cs.indiana.edu>
Reply-To: pell@boulder.Colorado.EDU (Anthony Pelletier)
Organization: University of Colorado, Boulder
Lines: 52

>internal.Apple.COM> <10659@boulder.Colorado.EDU>
>Reply-To: chiaravi@silver.bacs.indiana.edu (Lucius Chiaraviglio)
>Organization: Department of Biology at Indiana University, Bloomington
>Lines: 40
>


pell@boulder.Colorado.EDU (Anthony >Pelletier) writes:
>>[. . .] Me:

[Oversimplified hypothetical model for difference in muscle performance]
>

(Lucius Chiaraviglio) writes:
>	Actually, this won't do what you want.  The problem is that a cell

[a bit more detail, mostly correct, about muscle]

I won't contend with you on details since, as my posting said, I was not
intending to give details.  The point was that there is a rate limiting
step to muscle contraction and that different forms of the enzymes involved
would alter the overall rate.  I trust you have no disagreements with this?
I chose MLCK as a rate limiting step because it makes sense and there is
evidence in mouse muscle that different isoforms lead to different contraction
rate ex vivo.  I agree that the ATP regenerating system (and Lactate removal)
is also a key part of this (sorry for leaving them out--was trying to cut
back on lines a bit).  I trust you will agree that there could be allelic
differences in these as well.

>
>>[. . .]
Why should we treat it differently
>>than, say, the difference in isoforms of Aldehyde Dehydrogenase between
>>Whites and Asians? (Many Asians have a slow form that leads them to be
>>sensitive to drinking alcohol)
>

>	One should be careful with talking about "fast" and "slow" isoforms of
>enzymes; while in this case it is fairly obvious that you are talking about
>the rate at which the enzyme functions, "fast" and "slow" are often used to
>refer to electrophoretic variants of an enzyme, whose speed of migration in an
>SDS-polyacrylamide gel is entirely independant of their enzymatic turnover
>rates!
>
>|   Lucius Chiaraviglio    |    Internet:  chiaravi@silver.bacs.indiana.edu

Gee...thanks for clearing that up for people who were confused...
But actually, since the slow form is really the slow form, either way
it works!  (my work on ALDH was entirely concerned with kinetics of inhibition,
so I think about rates.  I hope I confused noone by using an ambiguous term)

-tony