Why only L amino acids?(Why not?)

dallas at mcvax4.d48.lilly.com dallas at mcvax4.d48.lilly.com
Thu Jul 14 09:14:45 EST 1994


In article <Pine.3.89.9407131024.A2232-0100000 at fox.cce.usp.br>, szeinfel at FOX.CCE.USP.BR (Rafael N Szeinfeld) writes:
> 
> 	I would like to say tha Jim Miller's message is stupid and this 
> gives us a image of what he is. Now to Jim : if you don't have anything 
> serious to say be quiet.
> 				Rafael Iosef Najmanovich Szeinfeld
> 				(from south hemisphere)

Since Rafael has chosen to flame me globally (maybe justly) I will apologize
generally to all Australians although nothing more than a little jest (based on
my experience with Australians I've met, ie they have a sense of humor) was
intended.

Now I should also reply that I did have something serious to say and except the
mistake about the proteinaceous 'start' of life (I was thinking about the
Oparin hypothesis), RNA polymer might be the beginning of an ancestral
ribosomal system.  My other comments below still stand as serious discussion
and several posters have already commented about "chance", etc.

My major point is that in a teaching atmosphere it is sometimes better to start
the discussion with "I (we) don't know" then open the discussion to cause and
effect possibilities(chance happenings).

Gee, sorry I stepped on some egos--yes, that's a global flame.

Jim (with an address) Miller
Lilly Research Laboratories
Indianapolis,IN
e-mail jrm at lilly.com

> On 12 Jul 1994 dallas at mcvax4.d48.lilly.com wrote:
> 
>> I know much of the discussion has been on a serious note, but I tend to like
>> the "We don't know" theory the best.  Why blow smoke?
>> 
>> One thing I do like is that nature is parsimonious (thrifty for those
without >> $.25).  At some point (much like when Moses(aka Mel Brooks) came
down from the >> Mount and dropped one of THE THREE tablets), a choice was
made.
>> 
>> (see "History of the World-Part I")
>> 
>> Other explanations:
>>Life only existed in the Northern hemisphere( what was the structure of >>
Gondwana Land?).

For those discussing the cariolis effect, this is a serious question.

>> Does life exist in the Southern hemisphere today?  A joke to
>> my mates in Oz.
>> We all know the partiality of God to right-handers (if you think of the
protein >> helix) and that 'left' in Latin is 'sinister'.  God also picked
L-amino acids >> because he does have a sense of humor and likes to read a good
discussion on >> the net.
>> 
>> Now serious stuff but questions for thought.

My original quote-- is this serious enough for you Rafael?

>>>> Was the beginning of life proteinaceous or nucleic acid in nature?  I
thought >> it was AGREED to be proteinaceous.

(See above)

>> 
>> Should we separate the synthesis of proteins (ribosomal) v. peptides with >>
D-amino acids (non-ribosomal).  Absolutely!  What does it mean?  I don't know.
>>  >> Whatever the discussion, systems have to be placed in chronological >>
(evolutionary) order.  For example, can you have stereochemically favored >>
enzymatic reactions BEFORE the selection (a presumption) of L-amino acids?
>> 
>> I don't know still seems like the best option.  :-)
>> 
>> Jim Miller
>> Indianapolis, IN
>> 
>> 



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