Protein dan Enzim
KIMIA KLINIK
Clinical Significance
Peptid
e bond
α-helix
pH
Ionic strength
Temperature
Solvent (dielectric
constant)
Antibodies
Coenzymes
Electrophoresis
Isoelectric focusing
Clinical Significance
CONCENTRATION
♮
Total protein concentration
6-8 g/dL
♮ Selected protein
conct.
PATTERN
Depend on
protein
Selected Protein
Analysis
Hyperglycemia
(e.g. Diabetes Mellitus)
up to 25%
albumin glycosylated
nonenzymatically
Related with HbA1c in DM
Normal condition
8%
albumin glycosylated
nonenzymatically
Useful for assessing
diabetic control in
Total Protein Analysis
≥ 2 peptide bonds
Cu
2++ Protein
Cu
2+-Protein complex
–
OH
Less sensitive than Lowry
Protein Analysis
•
Skrining
•
Total protein 6-8 g/dL dengan 3,5-5 g/dL albumin
•
Pattern of serum protein in agarose electrophoresis
(Serum protein electrophoresis: SPE)
•
Skrining
•
Total protein 6-8 g/dL dengan 3,5-5 g/dL albumin
•
Pattern of serum protein in agarose electrophoresis
(Serum protein electrophoresis: SPE)
Methods: Protein
Elektroforesis
Prinsip: Pemisahan protein berdasarkan perbedaan
muatan &/atau bobot molekul
(metode standar elektroforesis)
Horizontal electrophoresis Cth. Agarose electrophoresis
Vertical electrophoresis
SPE Patterns/Serum
PEP
Modified from
SPE Patterns
Modified from
SPE Patterns
Modified from
Vithoulkas H. HomeoNews 2008;9:9-10
SPE Patterns
Modified from
Vithoulkas H. HomeoNews 2008;9:9-10
Large spike in γ region Homogenous Ig
O’Connel et al. Am Fam Physician 2005;71(1):105-112
McPherson & Pincus
Enzym
e
Kimia Klinik
ENZIM
Glossary
•
Proenzim (Zymogen)
•
Enzim
•
Holoenzim
•
Apoenzim
•
Koenzim/kofaktor
Plasma & Non-plasma
Specific Enzymes
Plasma
•
Normal ada di plasma
Plasma adalah tempat
aksinya
•
Konsentrasinya tinggi
dibanding organ
•
Cth. Enzim pd
koagulasi
Non-plasma
•
Plasma bukan tempat
aksinya
•
Konsentrasinya di
plasma rendah (normal
krn sel apoptosis)
•
Konsentrasi
meningkat???
Harper’s
•
Regenerasi &
penyimpanan ATP
•
CK-BB
type
: (CK-1)brain
•
CK-MB
:
(CK-2)hybrid type
•
CK-MM
:
(CK-3)Muscle type
Kreatin +
ATP
Kreatin fosfat +
ADP
Copyright ©2007 American College of Cardiology Foundation. Restrictions may apply.
Faktor yg mempengaruhi
nilai rentang enzim
•
Waktu sampling
•
MI: CK-MB: 6 jam
•
Usia
•
Gender:
massa otot,
olahraga,
konsentrasi hormon
•
Ras
•
Olahraga
Alkaline phosphatase
(U/L)
[AMP buffer, p-nitrophenyl
phosphate substrate,
30
oC]
<10 th
157 – 270
10 – 18 th
90 – 320
>18 th
40 – 100
CK serum
30 – 50 U/L
Pengukuran Konsentrasi
Enzim
Pengukuran Tidak
Langsung:
aktivitas enzim
1.
Single reaction
Pengukuran produk
atau substrat yg
dikatalisis oleh
enzim tsb
jarang
2.
Coupled
reaction
Pemeriksaan
Langsung:
Immunoassay
•
Monoclonal/polyc
lonal antibodies
•
Mengukur
konsentrasi enzim itu
sendiri
•
Suhu
•
Suhu dijaga dlm rentang ±0,1
o•
Perbedaan 10
o
aktivitas enzim meningkat 2xnya
•
pH
: pH optimum utk enzim aktif
•
Garam
•
Terlalu tinggi
aktivitas enzim turun drastis
•
Konsentrasi protein
:
•
Plasma manusia, protein: 70 g/L; Urin hampir tidak ada
•
Penambahan albumin pd pemeriksaan amilase di urin
(spike)
