December 04, 2006 (G3) Histidine

Histidine - the Descent of the Holy Spirit (G3)

December 04, 2006

In his masterwork, The Pirotechnia, the great 16th century metallurgist Vannoccio Biringuccio pointed out that when one embarks on any difficult task one always ought to begin by invoking the assistance of God - otherwise he might be invoking the demons! Indeed, it has long been the design of the Church to begin any difficult task (like ordaining priests, confirming young adults, or electing the Pope!) by invoking the assistance of the Holy Spirit. This is nothing more than the miniature version of the Great Novena which the Apostles, together with Mary, spent in prayer, and which ended in the sending of the Holy Spirit, which we still do every year in the nine days after the Ascension.

Yesterday, as you well know, I did as Alice heard the King instruct the White Rabbit: to "begin with the beginning". However, another part of my design requires that I recall the first four Glorious Mysteries on the Sundays of Advent - but I cannot quite do that, since I've already explained the beginning yesterday, and I will have to explain the end on Christmas Eve (I've given away no secrets; you'll still be surprised!) So I will just use the standard trick which the Church uses, and deal with things as soon as I can. (If you don't know about that, I'll explain some other time.)

So, today we turn to the Holy Spirit and ask that He guide us to a deeper grasp of the mysteries - in particular by pondering the mystery of Pentecost, when He came in the form of tongues of fire upon the Apostles and Mary. This great mystery is the completion of the Paschal feast (Pentecost means fiftieth) - the "week of weeks" or "great octave" which comes fifty days after the Passover and Easter. To symbolize this mystery, I have selected the amino acid called Histidine:



Histidine (abbreviated His, or H)

RNA Codes:

C A U
C A C

Since this is the first amino acid we are examining, I must point out a few things now - some of which will be much more clear in a day or two once you have seen some more. Every amino acid has one central carbon atom. (In the diagram, it's the second one in from the left.) Carbon has four bonds, and in an amino acid, that carbon is attached to four different things:

1. a hydrogen atom (below the central carbon)
2. an NH₂ group. This is called an "amine", and so the whole is called an amino acid. (It sticks up, like a Y, from the central carbon.)
3. a COOH group. This is called a "carboxylic acid" and so the whole is called an amino acid They are rather weak acids, not at all like the kind in car batteries or used in industry. (The carboxyl carbon is the leftmost C; one oxygen (O) is connected with a double bond, and the other O has the H attached.)
4. Something else, which is called the "side chain" and which gives the "proper name" to the specific amino acid being considered.

Also: since this is the first one of the Glorious Mysteries I am considering, I will first explain the symbolism I am using. Five of the 20 amino acids have side chains which contain "ring structures" where the atoms are connected in the form of a loop. Like the wedding ring which has no end, this shape hints at the mysteries which lie on "other side" of our Lord's death.

According to one reference, Histidine is "positively charged, but only weakly at neutral pH". Here, we are reminded of the weakness of the Apostles, waiting in the Upper Room. Its "side chain" (the part which is unique to this amino acid), is made of a methyl - the CH₂ group - and a ring of five atoms: carbon, nitrogen, carbon, nitrogen, carbon. Because of the double bonds, there are only three more hydrogens in the ring, thus amounting to 11 atoms, suggesting the Eleven before the selection of Matthias. There is a very distinct Marian aspect (see Acts 1:14) to this mystery; as we shall see when we examine the amino acids for the two later Glorious Mysteries, the ring of Histidine contains nitrogen. (Of course every amino acid has a nitrogen, but I refer to the "side-chain" part.)

As I look at the diagram, I must tell you that am not very happy with it. The ring of the five atoms might look much more like a pentagon. But I wrote that program some time ago, and as I see now, I never bothered to fix certain things. (And I do not have time to fix it now!) It is not quite so nice for my first diagram, but it is good for me to admit my shortcomings Indeed, it struck me that there are times when I have not been as careful in my meditating on the Mysteries as I should be.

Yet, the Holy Spirit assists us in our weakness, and helps us to pray as we ought... (See Romans 8:26)