G. Krampitz

Aminotransferase activity of thermal polylysine

Thermisch hergestelltes Polylysin beschleunigt die Übertragung von Aminogruppen des Harnstoffs auf α-Ketoglutarsäure. Das pH-Optimum dieser Reaktion, die die Anwesenheit von Cu-Ionen erfordert, liegt bei 7.00. Die Transaminierungsreaktion folgt derMichaelis-Menten-Kinetik. Thermisch hergestelltes Polylysin wird durch Erhitzen in Pufferlösungen nicht inaktiviert, während Depolymerisation oder Modifizierungen der Aminogruppen den Verlust der Aktivität zur Folge haben.

Soluble matrix components in malformed oyster shells

Soluble proteins isolated from normal and malformed oyster shells have been partly characterized indicating remarkable differences in chemical composition and Ca2+-binding properties.

Calcium-binding peptide in dinosaur egg shells

1. Wfithrich, K.: NMR in Biological Research: Peptides and Proteins. Amsterdam: North-Holland 1976; Dwek, R.A. : Nuclear Magnetic Resonance in Biochemistry. Oxford: Clarendon Press 1973 2. Aue, W.P., Karhan, J., Ernst, R.R.: J. Chem. Phys. 64, 4226 (1976); Kumar, A., et al.: Proc. XIXth Congres Amp6re, Heidelberg, p. 473 (1976) 3. Hahn, E.L., Maxwell, D.E. : Phys. Rev. 88, 1070 (1952) 4. Mfiller, L., Kumar, A., Ernst, R.R.: J. Chem. Phys. 63, 5490 (1975); Bodenhausen, G., Freeman, R., Turner, D.L.: ibid. 65, 839 (1976); Mtiller, L., Kumar, A., Ernst, R.R.: J. Magn. Resonance 25, 383 (1977); Hester, R.K., etal.: Phys. Rev. Lett. 36, 1081 (1976) 5. Jeener, J.: Amp+re Int. Summer School II, Basko Polje (1971) 6. Aue, W.P., Bartholdi, E., Ernst, R.R.: J. Chem. Phys. 64, 2229 (1976) 7. Maudsley, A.A., Ernst, R.R. : Chem. Phys. Lett. (in press) 8. Vega, S., Shatmck, T.W., Pines, A.: Phys. Rev. Lett. 37, 43 (1976) ; Wokaun, A., Ernst, R.R. : submitted

Simultaneous binding of calcium and bicarbonate by conchiolin of oyster shells

Conchiolin of oyster shells selectively binds Ca2+. Bicarbonate is also bound but can be displaced by phosphate and sulfate. Conchiolin can be extracted to yield individual proteins with very high apparent molecular weights.

Über das Vorkommen von Carboanhydratase in der Eischale des Huhnes

The isolation of carbonic anhydrase from hens egg shells is reported. The enzyme has been purified by gelfiltration and ion-exchange chromatography. The elution pattern of carbonic anhydrase from egg shells differs remarkably from that of enzyme preparations of erythrocytes. The purified enzyme catalyzed the reversible hydration of CO2 and aldehydes as well as the hydrolysis ofp-nitrophenyl acetate. Deletion of 2-mercaptoethanol from extraction and elution buffer solutions caused a complete loss of carbonic anhydrase activity, as did the addition ofp-mercuribenzoate. The biological significance of the occurance of carbonic anhydrase in the hens egg shell is discussed.

Glutaminsäure-Oxydoreduktase-Aktivität von Polyanhydro-α-Aminosäuren (Proteinoiden)

Dieser U m s t a n d d e u t e t da r au f hin, dab das mark ie r t e Molekfil d u t c h di rekte W e c h s e l w i r k u n g des r ad ioak t iven A t o m s mi t e inem einzelilen Fgngermolekf l l en t s t eh t . Bet d i rekter Wechse lw i rkung k 6 n n e n n~ml ich keine Ace ty l ace tona t e gebi ldet werden, dereil Ligai ldei lzahl gr613er als die des Fgnger molekfils ist. Die B i ldung s p a l t p r o d u k t m a r k i e r t e r Ace t y l ace t ona t e b e r u h t sehr wahrsche in l i ch n ich t auI eiiler d i rek ten H o t A t o m Reak t ion , soi ldern auf I o n e n a u s t a u s c h im Fes tk6 rpe r : Es k o n n t e gezeigt werden, dab S p a l t r u t h e n i u m , das l~ngere Zei t nach seiilem E n t s t e h e n au f die Oberf lgche yon Co(acac)aKr is ta l len geb rach t wurde, m i t d iesen ebeilfalls zu m a r k i e r t e m Ru(acac)a reagiert . E in derar t iger A u s t a u s c h w u r d e unse res Wissens in Molekfi lgi t tern b i sher n u r zwischen i so topen Atomei l b e k a n n t [3].

Untersuchungen über Ultrastruktur und Aminosäurenzusammensetzung der Eischalen vonNatrix natrix

The ultrastructures of eggshells ofNatrix natrix and the membrana testacea ofGallus gallus dom. are very similar, with the exception of cavity systems which only exist in eggshells of snakes (ringsnake) but not in the membrana testacea of birds. In the sheath of the fibres ofNatrix natrix, a positive ruthenium redreaction indicates the presence of mucopolysacharides, or proteoglycans. The eggshells ofNatrix natrix contain a high proportion of proline, but also of cystine, histidine and arginine. The high proline content is discussed with regard to the properties of poly-l-proline. Presumably proteins similar to collagen exist in eggshells ofNatrix natrix.